Letting user know that application.js has also been written

For `ember build` I was seeing:

   created:	./templates.js
   created:	./index.js

... but application.js was getting created (and I scratched my head a little as to why,) so this commit is to make sure that output will be:

   created:	./templates.js
   created:	./index.js
   created:	./application.js