fix(build): fix AOT issues when building for production

See angular/angular-cli#7113. Additionally, remove no longer needed fix to yarn issue (yarnpkg/yarni#3485).

Author: zuzust

package.json

@@ -17,7 +17,7 @@
   ],
   "private": true,
   "scripts": {
-    "postinstall": "npm rebuild node-sass",
+    "postinstall": "npm install [email protected]",
     "ng": "ng",
     "start": "ng serve",
     "build": "ng build",