title: ui-select2 and ng-required
body: <p>I'm having problems using require/ng-require with the ui-select2 component. I wrapped the ui-select2 in a custom directive for reasons of reusability, but can't get the required to work with it.</p>
  
  <p>This is the plunker: <a href="http://plnkr.co/edit/2NaGvDWoEw14BN2few9W?p=preview" rel="nofollow">http://plnkr.co/edit/2NaGvDWoEw14BN2few9W?p=preview</a></p>
  
  <p>Tried without the directive and it's working: <a href="http://plnkr.co/edit/uE698iFcUNnsYVF2fkOO?p=preview" rel="nofollow">http://plnkr.co/edit/uE698iFcUNnsYVF2fkOO?p=preview</a></p>