add environmentSource in addition to environments.soruce to work with new version of cli (#125)

Author: mmalerba

angular-cli.json

@@ -22,6 +22,7 @@
         "highlightjs/solarized-light.css"
       ],
       "scripts": [],
+      "environmentSource": "environments/environment.ts",
       "environments": {
         "source": "environments/environment.ts",
         "dev": "environments/environment.ts",