Add CommonJs Support

Author: dchambers

package.json

@@ -8,7 +8,7 @@
     "Peggy Rayzis <peggy@meteor.com>"
   ],
   "license": "MIT",
-  "main": "./lib/index.js",
+  "main": "./lib/cjs/index.js",
   "module": "./lib/index.js",
   "jsnext:main": "./lib/index.js",
   "typings": "./lib/index.d.ts",
@@ -20,7 +20,7 @@
   "bugs": "https://github.com/apollographql/apollo-cache-persist/issues",
   "scripts": {
     "build:browser": "browserify ./lib/bundle.umd.js -o=./lib/bundle.js && npm run minify:browser",
-    "build": "tsc -p .",
+    "build": "tsc -p . && tsc -p ./tsconfig.cjs.json",
     "bundle": "rollup -c",
     "clean": "rimraf lib/* && rimraf coverage/*",
     "coverage:upload": "codecov",

tsconfig.cjs.json

@@ -0,0 +1,7 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "outDir": "lib/cjs",
+    "module": "commonjs"
+  }
+}