title: How can I run an acceptance test?
body: <p>I have the following <code>tests/acceptance/index-test.js</code> in an ember-cli version 0.0.22 app:</p>
  
  <pre><code>import startApp from '../helpers/start-app';
  test('index transitions', function(){
    visit('/');
  });
  </code></pre>
  
  <p>When I go to <code>http://localhost:4200/tests</code> I see:</p>
  
  <pre><code>Died on test #1
  at eval (ember-cli/tests/acceptance/index-test.js:7:5)
  at requireModule (loader/loader.js:54:29)
  at eval (ember-cli/tests/test-loader.js:9:7)
  at Array.forEach (native)
  at eval (ember-cli/tests/test-loader.js:8:8)
  at requireModule (loader/loader.js:54:29)
  at http://localhost:4200/tests:43:7: visit is not defined
  
  Source: ReferenceError: visit is not defined
  at Object.eval (ember-cli/tests/acceptance/index-test.js:8:7)
  </code></pre>
  
  <p>It seems I'm having trouble loading code. Placeholder files in the project would be useful. How can I make it work?</p>