title: The select2('val') method was called on an element that is not using Select2
body: <p>I'm having problem with implementing Select2 into my application. The documentation is pretty straight forward but for some reason I cannot even do the simplest example with multiple selection.</p>
  
  <p>I have created a plunker with an example <a href="https://plnkr.co/edit/v4vPlMgyL7oJe2EjFc6r?p=preview" rel="nofollow">here</a></p>
  
  <pre><code>&lt;div ng-controller="MyCtrl"&gt;
    &lt;select style="width: 400px;" ui-select2="select2Options" multiple ng-model="selectedTags"&gt;
      &lt;option ng-repeat="tag in tags" value="{{tag.id}}"&gt;{{tag.name}}&lt;/option&gt;
  &lt;/select&gt;
  &lt;/div&gt;
  
  
  myApp.controller('MyCtrl', function($scope) {
  $scope.tags = [
      {id: 0, name: "Zero"},
      {id: 1, name: "One"},
      {id: 2, name: "Two"}, 
      {id: 3, name: "Three"}, 
      {id: 4, name: "Four"}, 
  ];
  
  $scope.select2Options = {
          allowClear: true,
          multiple: true
      };
  
  })
  </code></pre>