title: How to access needs elements in ember-cli unit test
body: <p>In a route test I need to access a service, to retrieve a model.
  I have referenced the service via needs, but inside the test I don't see a way of accessing the service. </p>
  
  <pre><code>import {
    moduleFor,
    test
  } from 'ember-qunit';
  
  
  moduleFor('route:application', {
    needs: ['route:application','controller:application','service:dialog']
  });
  
  test('can open and remove a dialog dialog', function(assert) {
      var route = this.subject();
      route.setProperties({
        controller: { // don't like this part as well .. 
          dialogs:null
        }
      });
  
      // need to access the service here to get a model
      // something like :
      //var service = this.get('service:dialog');
      var modalModel = service.getModal('business/contract-edit');
  
      ...
  
  
  });
  </code></pre>
  
  <p>How can I access the service inside the test?</p>
  
  <p>(BTW: I'm using ember v2.0.0)</p>