correctly setup for ember-qunit

I had some difficulties testing components until I haven't discovered that you need to have `#ember-testing` div and `App.rootElement` set exactly to `ember-testing`. I've reported an issue [here](https://github.com/rpflorence/ember-qunit/issues/40).
Merge pull request #1456 from zigomir/patch-5

correctly setup for ember-qunit