title: Select custom directive and ng-change
body: <p>Using <code>&lt;select&gt;</code> with a custom directive, I want to run a function when the value is changed.</p>
  
  <p>html</p>
  
  <pre><code>&lt;select name="user_type" ng-model="user_type" user-type ng-change="check_type()"&gt;
  </code></pre>
  
  <p>directive</p>
  
  <pre><code>gb_dash.directive('userType', function(){
      return{
          restrict: 'A',
          require: '^ngModel',
          scope:{
              check_type: '&amp;'
          },
          link: function(scope, elem, attrs){
              scope.check_type = function(){
                  console.log('changed');
              }
          }
      }
  });
  </code></pre>