title: angular material md-button ng-click doesn't work
body: <p>md-button with ng-click doesn't work.
  So I created simple controller like following.
  Wen I clicked button2 its works, but click md-button nothing happening.</p>
  
  <p><strong>controller</strong></p>
  
  <pre><code>app.controller('MyContrl', function ($scope) {
      $scope.submit = function () {
          $scope.message = "asdfa";
      };
  });
  </code></pre>
  
  <p><strong>html</strong> </p>
  
  <pre><code>{{message}}
  &lt;md-input-container&gt;
      &lt;md-button ng-click="sumit()"&gt;Button1 - Doesn't work&lt;/md-button&gt;
  &lt;/md-input-container&gt;
  &lt;button ng-click="submit()" value="Button2- works" class="md-raised"&gt;sdf&lt;/button&gt;
  </code></pre>