chore(package): update prettier to version 2.0.5

Closes #41

Author: greenkeeper[bot]

package.json

@@ -13,7 +13,7 @@
     "@types/jest": "^25.1.1",
     "@vue/test-utils": "^1.0.0-beta.31",
     "jest": "^25.1.0",
-    "prettier": "^1.18.2",
+    "prettier": "^2.0.5",
     "prettylint": "^1.0.0",
     "rxjs": "^6.5.2",
     "ts-jest": "^25.1.0",