remove postinstall

package.json

@@ -5,14 +5,13 @@
   "main": "src/index.js",
   "types": "types/index.d.ts",
   "scripts": {
-    "start": "cd example && npm run start",
+    "start": "cd example && npm i && npm run start",
     "npm-cli-login": "npm-cli-login",
     "pre-commit": "pretty-quick --staged && npm run tslint",
     "pre-push": "npm run pre-commit",
     "tslint": "tslint -c tslint.json 'types/**/*.d.ts' 'src/**/*.d.ts'",
     "tslint:fix": "npm run tslint -- --fix",
-    "test": "echo \"Error: no test specified\" && exit 1",
-    "postinstall": "cd example && npm i"
+    "test": "echo \"Error: no test specified\" && exit 1"
   },
   "repository": {
     "type": "git",