chore: move zone.js as the last loaded polyfill. (#623)

Fixes #621

Author: hansl

addon/ng2/blueprints/ng2/files/__path__/index.html

@@ -26,9 +26,9 @@
 
   <script src="vendor/es6-shim/es6-shim.js"></script>
   <script src="vendor/reflect-metadata/Reflect.js"></script>
-  <script src="vendor/zone.js/dist/zone.js"></script>
   <script src="vendor/systemjs/dist/system-polyfills.js"></script>
   <script src="vendor/systemjs/dist/system.src.js"></script>
+  <script src="vendor/zone.js/dist/zone.js"></script>
 
   <script>
     System.import('system-config.js').then(function () {