Upgrade Carousel to use the new $interval service.

The $timeout polling causes angular/protractor tests to fail. As described [here](https://github.com/angular/protractor/blob/master/docs/faq.md#my-tests-time-out-in-protractor-but-everythings-working-fine-when-running-manually-whats-up)  The $interval service was introduced in Angular 1.2. 
