Use $interval instead of $timeout in the carousel implementation

[pkozlowski-opensource]

Based on #1630 (comment)

[Gahen]

Hey guys! The PR I sent solves an important issue for those of us who are using protractor and this lib's carousel. As @juliemr said, protractor waits for all $timeout to finish, so with out the patch it hangs forever.

There is no nice and simple workaround, I had to patch it and use my version to avoid this issue.

[Splaktar]

I am running into the issue that @Gahen is mentioning. We just upgraded to the latest carousel and now our protractor tests are completely broken. I tried a few different approaches but so far they aren't working. This seems to be the same thing that has been an issue for almost a year now. See issue #1308.