Enable e2e testing with angular-timeago

At the current state, protractor hangs when having `angular-timeago` in use. This is due to the usage of `$timeout`. There is a very easy solution for this which was also done by https://github.com/urish/angular-moment/issues/19, namely to change the usage of `$timeout` with `$window.setTimeout` allowing an identical functionality but yet allowing protractor to run its assertions between timeout cycles. Accepting this functionality is crucial for `angular-timeago` to stay useful for real world application.

If there's anything you think I need to add or change, please let me know and I will do so.

Thanks for creating this,

Amit.