diff --git a/package-lock.json b/package-lock.json
index 5c2ce78..d42faa7 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -8,6 +8,7 @@
       "version": "0.0.7-SNAPSHOT",
       "license": "GPL-3.0",
       "dependencies": {
+        "html-minifier": "^4.0.0",
         "serverless": "^2.46.0"
       },
       "devDependencies": {
@@ -2222,6 +2223,15 @@
         "node": ">=6"
       }
     },
+    "node_modules/camel-case": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/camel-case/-/camel-case-3.0.0.tgz",
+      "integrity": "sha1-yjw2iKTpzzpM2nd9xNy8cTJJz3M=",
+      "dependencies": {
+        "no-case": "^2.2.0",
+        "upper-case": "^1.1.1"
+      }
+    },
     "node_modules/camelcase": {
       "version": "6.2.0",
       "resolved": "https://registry.npmjs.org/camelcase/-/camelcase-6.2.0.tgz",
@@ -2320,6 +2330,17 @@
       "resolved": "https://registry.npmjs.org/ci-info/-/ci-info-3.2.0.tgz",
       "integrity": "sha512-dVqRX7fLUm8J6FgHJ418XuIgDLZDkYcDFTeL6TA2gt5WlIZUQrrH6EZrNClwT/H0FateUsZkGIOPRrLbP+PR9A=="
     },
+    "node_modules/clean-css": {
+      "version": "4.2.3",
+      "resolved": "https://registry.npmjs.org/clean-css/-/clean-css-4.2.3.tgz",
+      "integrity": "sha512-VcMWDN54ZN/DS+g58HYL5/n4Zrqe8vHJpGA8KdgUXFU4fuP/aHNw8eld9SyEIyabIMJX/0RaY/fplOo5hYLSFA==",
+      "dependencies": {
+        "source-map": "~0.6.0"
+      },
+      "engines": {
+        "node": ">= 4.0"
+      }
+    },
     "node_modules/cli-boxes": {
       "version": "2.2.1",
       "resolved": "https://registry.npmjs.org/cli-boxes/-/cli-boxes-2.2.1.tgz",
@@ -3667,6 +3688,34 @@
       "integrity": "sha1-4Ob+aijPUROIVeCG0Wkedx3iqLk=",
       "optional": true
     },
+    "node_modules/he": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/he/-/he-1.2.0.tgz",
+      "integrity": "sha512-F/1DnUGPopORZi0ni+CvrCgHQ5FyEAHRLSApuYWMmrbSwoN2Mn/7k+Gl38gJnR7yyDZk6WLXwiGod1JOWNDKGw==",
+      "bin": {
+        "he": "bin/he"
+      }
+    },
+    "node_modules/html-minifier": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/html-minifier/-/html-minifier-4.0.0.tgz",
+      "integrity": "sha512-aoGxanpFPLg7MkIl/DDFYtb0iWz7jMFGqFhvEDZga6/4QTjneiD8I/NXL1x5aaoCp7FSIT6h/OhykDdPsbtMig==",
+      "dependencies": {
+        "camel-case": "^3.0.0",
+        "clean-css": "^4.2.1",
+        "commander": "^2.19.0",
+        "he": "^1.2.0",
+        "param-case": "^2.1.1",
+        "relateurl": "^0.2.7",
+        "uglify-js": "^3.5.1"
+      },
+      "bin": {
+        "html-minifier": "cli.js"
+      },
+      "engines": {
+        "node": ">=6"
+      }
+    },
     "node_modules/http-cache-semantics": {
       "version": "4.1.0",
       "resolved": "https://registry.npmjs.org/http-cache-semantics/-/http-cache-semantics-4.1.0.tgz",
@@ -4395,6 +4444,11 @@
         "node": ">=0.6"
       }
     },
+    "node_modules/lower-case": {
+      "version": "1.1.4",
+      "resolved": "https://registry.npmjs.org/lower-case/-/lower-case-1.1.4.tgz",
+      "integrity": "sha1-miyr0bno4K6ZOkv31YdcOcQujqw="
+    },
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       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/lowercase-keys/-/lowercase-keys-1.0.1.tgz",
@@ -4654,6 +4708,14 @@
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     },
+    "node_modules/no-case": {
+      "version": "2.3.2",
+      "resolved": "https://registry.npmjs.org/no-case/-/no-case-2.3.2.tgz",
+      "integrity": "sha512-rmTZ9kz+f3rCvK2TD1Ue/oZlns7OGoIWP4fc3llxxRXlOkHKoWPPWJOfFYpITabSow43QJbRIoHQXtt10VldyQ==",
+      "dependencies": {
+        "lower-case": "^1.1.1"
+      }
+    },
     "node_modules/node-abi": {
       "version": "2.30.0",
       "resolved": "https://registry.npmjs.org/node-abi/-/node-abi-2.30.0.tgz",
@@ -4882,6 +4944,14 @@
       "resolved": "https://registry.npmjs.org/pako/-/pako-1.0.11.tgz",
       "integrity": "sha512-4hLB8Py4zZce5s4yd9XzopqwVv/yGNhV1Bl8NTmCq1763HeK2+EwVTv+leGeL13Dnh2wfbqowVPXCIO0z4taYw=="
     },
+    "node_modules/param-case": {
+      "version": "2.1.1",
+      "resolved": "https://registry.npmjs.org/param-case/-/param-case-2.1.1.tgz",
+      "integrity": "sha1-35T9jPZTHs915r75oIWPvHK+Ikc=",
+      "dependencies": {
+        "no-case": "^2.2.0"
+      }
+    },
     "node_modules/parseqs": {
       "version": "0.0.6",
       "resolved": "https://registry.npmjs.org/parseqs/-/parseqs-0.0.6.tgz",
@@ -5278,6 +5348,14 @@
         "node": ">=8"
       }
     },
+    "node_modules/relateurl": {
+      "version": "0.2.7",
+      "resolved": "https://registry.npmjs.org/relateurl/-/relateurl-0.2.7.tgz",
+      "integrity": "sha1-VNvzd+UUQKypCkzSdGANP/LYiKk=",
+      "engines": {
+        "node": ">= 0.10"
+      }
+    },
     "node_modules/replaceall": {
       "version": "0.1.6",
       "resolved": "https://registry.npmjs.org/replaceall/-/replaceall-0.1.6.tgz",
@@ -6163,6 +6241,14 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/source-map": {
+      "version": "0.6.1",
+      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
+      "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==",
+      "engines": {
+        "node": ">=0.10.0"
+      }
+    },
     "node_modules/split2": {
       "version": "3.2.2",
       "resolved": "https://registry.npmjs.org/split2/-/split2-3.2.2.tgz",
@@ -6931,6 +7017,17 @@
         "is-typedarray": "^1.0.0"
       }
     },
+    "node_modules/uglify-js": {
+      "version": "3.13.9",
+      "resolved": "https://registry.npmjs.org/uglify-js/-/uglify-js-3.13.9.tgz",
+      "integrity": "sha512-wZbyTQ1w6Y7fHdt8sJnHfSIuWeDgk6B5rCb4E/AM6QNNPbOMIZph21PW5dRB3h7Df0GszN+t7RuUH6sWK5bF0g==",
+      "bin": {
+        "uglifyjs": "bin/uglifyjs"
+      },
+      "engines": {
+        "node": ">=0.8.0"
+      }
+    },
     "node_modules/unbzip2-stream": {
       "version": "1.4.3",
       "resolved": "https://registry.npmjs.org/unbzip2-stream/-/unbzip2-stream-1.4.3.tgz",
@@ -6979,6 +7076,11 @@
         "node": ">=4"
       }
     },
+    "node_modules/upper-case": {
+      "version": "1.1.3",
+      "resolved": "https://registry.npmjs.org/upper-case/-/upper-case-1.1.3.tgz",
+      "integrity": "sha1-9rRQHC7EzdJrp4vnIilh3ndiFZg="
+    },
     "node_modules/uri-js": {
       "version": "4.4.1",
       "resolved": "https://registry.npmjs.org/uri-js/-/uri-js-4.4.1.tgz",
@@ -9109,6 +9211,15 @@
       "resolved": "https://registry.npmjs.org/cachedir/-/cachedir-2.3.0.tgz",
       "integrity": "sha512-A+Fezp4zxnit6FanDmv9EqXNAi3vt9DWp51/71UEhXukb7QUuvtv9344h91dyAxuTLoSYJFU299qzR3tzwPAhw=="
     },
+    "camel-case": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/camel-case/-/camel-case-3.0.0.tgz",
+      "integrity": "sha1-yjw2iKTpzzpM2nd9xNy8cTJJz3M=",
+      "requires": {
+        "no-case": "^2.2.0",
+        "upper-case": "^1.1.1"
+      }
+    },
     "camelcase": {
       "version": "6.2.0",
       "resolved": "https://registry.npmjs.org/camelcase/-/camelcase-6.2.0.tgz",
@@ -9186,6 +9297,14 @@
       "resolved": "https://registry.npmjs.org/ci-info/-/ci-info-3.2.0.tgz",
       "integrity": "sha512-dVqRX7fLUm8J6FgHJ418XuIgDLZDkYcDFTeL6TA2gt5WlIZUQrrH6EZrNClwT/H0FateUsZkGIOPRrLbP+PR9A=="
     },
+    "clean-css": {
+      "version": "4.2.3",
+      "resolved": "https://registry.npmjs.org/clean-css/-/clean-css-4.2.3.tgz",
+      "integrity": "sha512-VcMWDN54ZN/DS+g58HYL5/n4Zrqe8vHJpGA8KdgUXFU4fuP/aHNw8eld9SyEIyabIMJX/0RaY/fplOo5hYLSFA==",
+      "requires": {
+        "source-map": "~0.6.0"
+      }
+    },
     "cli-boxes": {
       "version": "2.2.1",
       "resolved": "https://registry.npmjs.org/cli-boxes/-/cli-boxes-2.2.1.tgz",
@@ -10294,6 +10413,25 @@
       "integrity": "sha1-4Ob+aijPUROIVeCG0Wkedx3iqLk=",
       "optional": true
     },
+    "he": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/he/-/he-1.2.0.tgz",
+      "integrity": "sha512-F/1DnUGPopORZi0ni+CvrCgHQ5FyEAHRLSApuYWMmrbSwoN2Mn/7k+Gl38gJnR7yyDZk6WLXwiGod1JOWNDKGw=="
+    },
+    "html-minifier": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/html-minifier/-/html-minifier-4.0.0.tgz",
+      "integrity": "sha512-aoGxanpFPLg7MkIl/DDFYtb0iWz7jMFGqFhvEDZga6/4QTjneiD8I/NXL1x5aaoCp7FSIT6h/OhykDdPsbtMig==",
+      "requires": {
+        "camel-case": "^3.0.0",
+        "clean-css": "^4.2.1",
+        "commander": "^2.19.0",
+        "he": "^1.2.0",
+        "param-case": "^2.1.1",
+        "relateurl": "^0.2.7",
+        "uglify-js": "^3.5.1"
+      }
+    },
     "http-cache-semantics": {
       "version": "4.1.0",
       "resolved": "https://registry.npmjs.org/http-cache-semantics/-/http-cache-semantics-4.1.0.tgz",
@@ -10896,6 +11034,11 @@
       "resolved": "https://registry.npmjs.org/long/-/long-1.1.2.tgz",
       "integrity": "sha1-6u9ZUcp1UdlpJrgtokLbnWso+1M="
     },
+    "lower-case": {
+      "version": "1.1.4",
+      "resolved": "https://registry.npmjs.org/lower-case/-/lower-case-1.1.4.tgz",
+      "integrity": "sha1-miyr0bno4K6ZOkv31YdcOcQujqw="
+    },
     "lowercase-keys": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/lowercase-keys/-/lowercase-keys-1.0.1.tgz",
@@ -11105,6 +11248,14 @@
       "resolved": "https://registry.npmjs.org/nice-try/-/nice-try-1.0.5.tgz",
       "integrity": "sha512-1nh45deeb5olNY7eX82BkPO7SSxR5SSYJiPTrTdFUVYwAl8CKMA5N9PjTYkHiRjisVcxcQ1HXdLhx2qxxJzLNQ=="
     },
+    "no-case": {
+      "version": "2.3.2",
+      "resolved": "https://registry.npmjs.org/no-case/-/no-case-2.3.2.tgz",
+      "integrity": "sha512-rmTZ9kz+f3rCvK2TD1Ue/oZlns7OGoIWP4fc3llxxRXlOkHKoWPPWJOfFYpITabSow43QJbRIoHQXtt10VldyQ==",
+      "requires": {
+        "lower-case": "^1.1.1"
+      }
+    },
     "node-abi": {
       "version": "2.30.0",
       "resolved": "https://registry.npmjs.org/node-abi/-/node-abi-2.30.0.tgz",
@@ -11272,6 +11423,14 @@
       "resolved": "https://registry.npmjs.org/pako/-/pako-1.0.11.tgz",
       "integrity": "sha512-4hLB8Py4zZce5s4yd9XzopqwVv/yGNhV1Bl8NTmCq1763HeK2+EwVTv+leGeL13Dnh2wfbqowVPXCIO0z4taYw=="
     },
+    "param-case": {
+      "version": "2.1.1",
+      "resolved": "https://registry.npmjs.org/param-case/-/param-case-2.1.1.tgz",
+      "integrity": "sha1-35T9jPZTHs915r75oIWPvHK+Ikc=",
+      "requires": {
+        "no-case": "^2.2.0"
+      }
+    },
     "parseqs": {
       "version": "0.0.6",
       "resolved": "https://registry.npmjs.org/parseqs/-/parseqs-0.0.6.tgz",
@@ -11560,6 +11719,11 @@
         "rc": "^1.2.8"
       }
     },
+    "relateurl": {
+      "version": "0.2.7",
+      "resolved": "https://registry.npmjs.org/relateurl/-/relateurl-0.2.7.tgz",
+      "integrity": "sha1-VNvzd+UUQKypCkzSdGANP/LYiKk="
+    },
     "replaceall": {
       "version": "0.1.6",
       "resolved": "https://registry.npmjs.org/replaceall/-/replaceall-0.1.6.tgz",
@@ -12222,6 +12386,11 @@
         "sort-keys": "^1.0.0"
       }
     },
+    "source-map": {
+      "version": "0.6.1",
+      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
+      "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g=="
+    },
     "split2": {
       "version": "3.2.2",
       "resolved": "https://registry.npmjs.org/split2/-/split2-3.2.2.tgz",
@@ -12834,6 +13003,11 @@
         "is-typedarray": "^1.0.0"
       }
     },
+    "uglify-js": {
+      "version": "3.13.9",
+      "resolved": "https://registry.npmjs.org/uglify-js/-/uglify-js-3.13.9.tgz",
+      "integrity": "sha512-wZbyTQ1w6Y7fHdt8sJnHfSIuWeDgk6B5rCb4E/AM6QNNPbOMIZph21PW5dRB3h7Df0GszN+t7RuUH6sWK5bF0g=="
+    },
     "unbzip2-stream": {
       "version": "1.4.3",
       "resolved": "https://registry.npmjs.org/unbzip2-stream/-/unbzip2-stream-1.4.3.tgz",
@@ -12864,6 +13038,11 @@
       "resolved": "https://registry.npmjs.org/untildify/-/untildify-3.0.3.tgz",
       "integrity": "sha512-iSk/J8efr8uPT/Z4eSUywnqyrQU7DSdMfdqK4iWEaUVVmcP5JcnpRqmVMwcwcnmI1ATFNgC5V90u09tBynNFKA=="
     },
+    "upper-case": {
+      "version": "1.1.3",
+      "resolved": "https://registry.npmjs.org/upper-case/-/upper-case-1.1.3.tgz",
+      "integrity": "sha1-9rRQHC7EzdJrp4vnIilh3ndiFZg="
+    },
     "uri-js": {
       "version": "4.4.1",
       "resolved": "https://registry.npmjs.org/uri-js/-/uri-js-4.4.1.tgz",
diff --git a/ui/package-lock.json b/ui/package-lock.json
deleted file mode 100644
index 47e6e30..0000000
--- a/ui/package-lock.json
+++ /dev/null
@@ -1,130 +0,0 @@
-{
-  "name": "plantuml-previewer",
-  "version": "1.0.0",
-  "lockfileVersion": 1,
-  "requires": true,
-  "dependencies": {
-    "camel-case": {
-      "version": "3.0.0",
-      "resolved": "https://registry.npmjs.org/camel-case/-/camel-case-3.0.0.tgz",
-      "integrity": "sha1-yjw2iKTpzzpM2nd9xNy8cTJJz3M=",
-      "dev": true,
-      "requires": {
-        "no-case": "2.3.2",
-        "upper-case": "1.1.3"
-      }
-    },
-    "clean-css": {
-      "version": "4.1.11",
-      "resolved": "https://registry.npmjs.org/clean-css/-/clean-css-4.1.11.tgz",
-      "integrity": "sha1-Ls3xRaujj1R0DybO/Q/z4D4SXWo=",
-      "dev": true,
-      "requires": {
-        "source-map": "0.5.7"
-      }
-    },
-    "commander": {
-      "version": "2.15.1",
-      "resolved": "https://registry.npmjs.org/commander/-/commander-2.15.1.tgz",
-      "integrity": "sha512-VlfT9F3V0v+jr4yxPc5gg9s62/fIVWsd2Bk2iD435um1NlGMYdVCq+MjcXnhYq2icNOizHr1kK+5TI6H0Hy0ag==",
-      "dev": true
-    },
-    "he": {
-      "version": "1.1.1",
-      "resolved": "https://registry.npmjs.org/he/-/he-1.1.1.tgz",
-      "integrity": "sha1-k0EP0hsAlzUVH4howvJx80J+I/0=",
-      "dev": true
-    },
-    "html-minifier": {
-      "version": "3.5.12",
-      "resolved": "https://registry.npmjs.org/html-minifier/-/html-minifier-3.5.12.tgz",
-      "integrity": "sha512-+N778qLf0RWBscD0TPGoYdeGNDZ0s76/0pQhY1/409EOudcENkm9IbSkk37RDyPdg/09GVHTKotU4ya93RF1Gg==",
-      "dev": true,
-      "requires": {
-        "camel-case": "3.0.0",
-        "clean-css": "4.1.11",
-        "commander": "2.15.1",
-        "he": "1.1.1",
-        "ncname": "1.0.0",
-        "param-case": "2.1.1",
-        "relateurl": "0.2.7",
-        "uglify-js": "3.3.16"
-      }
-    },
-    "lower-case": {
-      "version": "1.1.4",
-      "resolved": "https://registry.npmjs.org/lower-case/-/lower-case-1.1.4.tgz",
-      "integrity": "sha1-miyr0bno4K6ZOkv31YdcOcQujqw=",
-      "dev": true
-    },
-    "ncname": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/ncname/-/ncname-1.0.0.tgz",
-      "integrity": "sha1-W1etGLHKCShk72Kwse2BlPODtxw=",
-      "dev": true,
-      "requires": {
-        "xml-char-classes": "1.0.0"
-      }
-    },
-    "no-case": {
-      "version": "2.3.2",
-      "resolved": "https://registry.npmjs.org/no-case/-/no-case-2.3.2.tgz",
-      "integrity": "sha512-rmTZ9kz+f3rCvK2TD1Ue/oZlns7OGoIWP4fc3llxxRXlOkHKoWPPWJOfFYpITabSow43QJbRIoHQXtt10VldyQ==",
-      "dev": true,
-      "requires": {
-        "lower-case": "1.1.4"
-      }
-    },
-    "param-case": {
-      "version": "2.1.1",
-      "resolved": "https://registry.npmjs.org/param-case/-/param-case-2.1.1.tgz",
-      "integrity": "sha1-35T9jPZTHs915r75oIWPvHK+Ikc=",
-      "dev": true,
-      "requires": {
-        "no-case": "2.3.2"
-      }
-    },
-    "relateurl": {
-      "version": "0.2.7",
-      "resolved": "https://registry.npmjs.org/relateurl/-/relateurl-0.2.7.tgz",
-      "integrity": "sha1-VNvzd+UUQKypCkzSdGANP/LYiKk=",
-      "dev": true
-    },
-    "source-map": {
-      "version": "0.5.7",
-      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.5.7.tgz",
-      "integrity": "sha1-igOdLRAh0i0eoUyA2OpGi6LvP8w=",
-      "dev": true
-    },
-    "uglify-js": {
-      "version": "3.3.16",
-      "resolved": "https://registry.npmjs.org/uglify-js/-/uglify-js-3.3.16.tgz",
-      "integrity": "sha512-FMh5SRqJRGhv9BbaTffENIpDDQIoPDR8DBraunGORGhySArsXlw9++CN+BWzPBLpoI4RcSnpfGPnilTxWL3Vvg==",
-      "dev": true,
-      "requires": {
-        "commander": "2.15.1",
-        "source-map": "0.6.1"
-      },
-      "dependencies": {
-        "source-map": {
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-          "dev": true
-        }
-      }
-    },
-    "upper-case": {
-      "version": "1.1.3",
-      "resolved": "https://registry.npmjs.org/upper-case/-/upper-case-1.1.3.tgz",
-      "integrity": "sha1-9rRQHC7EzdJrp4vnIilh3ndiFZg=",
-      "dev": true
-    },
-    "xml-char-classes": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/xml-char-classes/-/xml-char-classes-1.0.0.tgz",
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-}
diff --git a/ui/package.json b/ui/package.json
deleted file mode 100644
index 5c6475d..0000000
--- a/ui/package.json
+++ /dev/null
@@ -1,23 +0,0 @@
-{
-  "name": "plantuml-previewer",
-  "version": "1.0.0",
-  "description": "Online Plant UML editor with syntax highlighting and preview.",
-  "main": "index.js",
-  "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1"
-  },
-  "repository": {
-    "type": "git",
-    "url": "git+https://github.com/mmajis/plantuml-previewer.git"
-  },
-  "author": "",
-  "license": "ISC",
-  "bugs": {
-    "url": "https://github.com/mmajis/plantuml-previewer/issues"
-  },
-  "homepage": "https://github.com/mmajis/plantuml-previewer#readme",
-  "dependencies": {},
-  "devDependencies": {
-    "html-minifier": "^3.5.12"
-  }
-}