title: angularjs ui-router set active link doesn't work
body: <p>I'm trying to set an active link
  on the current tab like</p>
  
  <pre><code>in jade
  ul.nav.navbar-nav
                              li(ng-class="{ active: $state.includes('index') }")
                                  a(ui-sref='index') Home
                              li(ng-class="{ active: $state.includes('post') }")
                                  a(ui-sref='post') Post
   html
  &lt;li ng-class="{ active: $state.includes('index') }"&gt;&lt;a ui-sref="index" href="#/"&gt;Home&lt;/a&gt;&lt;/li&gt;
                &lt;li ng-class="{ active: $state.includes('post') }"&gt;&lt;a ui-sref="post" href="#/post"&gt;Post&lt;/a&gt;&lt;/li&gt;
  
  
  
  
  js   .config(function($stateProvider,RestangularProvider,PostProvider,PostsProvider,MediaProvider) {
              $stateProvider
                  .state('index', {
                      url: '/',
                      templateUrl: 'admin/views/index.html',
                      controller: 'HomeCtrl'
                  })
                  .state('post', {
                      url: '/post',
                      templateUrl: 'admin/views/post/index.html',
                      resolve: {
                          posts: function(Posts){
                              return Posts.all();
                          }
                      },
                      controller: 'PostIndexCtrl'
                  })
  </code></pre>
  
  <p>but it doesn't work. 
  But if I try to check it:</p>
  
  <pre><code>.controller('PostIndexCtrl', function ($scope,posts,$state) {
          $scope.posts = posts;
          console.log($state.includes('post'));
      })
  </code></pre>
  
  <p>give me true.</p>
  
  <p>Do you know what's the problem ?</p>