Add ngCordova

ngCordova will add native capabilities to the app.
It's wrapping cordova plugins which should be installed separately and
use them by injecting the appropriate modules to the app.
For more info:
http://ngcordova.com/

PS - To wrap the app to iOS or android, yes ionic command line (ionic
platform add ios...)
Update index.js
Update module.test.js
Update _package.json