title: AngularJS $animate.addClass requires $timeout
body: <p>I'm having some unexpected behaviour where the $animate service's addClass method is not adding the appropriate -add and -add-active classes.</p>
  
  <p>The same use of the service, wrapped in a $timeout, seems to work as expected:
  <a href="http://plnkr.co/edit/3sFGp4y2WGA0HReIglR3?p=preview" rel="nofollow">http://plnkr.co/edit/3sFGp4y2WGA0HReIglR3?p=preview</a></p>
  
  <p>Obviously, using unnecessary $timeouts is something I would like to avoid.</p>
  
  <p>Am I missing something, or using the service incorrectly?</p>