Inject real service in Ember.js test

There is no straightforward howto on injecting real services in Ember components/controllers/routes when you test them, instead of mocking them.

Well. I just do this dirty thing:

`import startApp from 'listly/tests/helpers/start-app'`
 ...
 App = startApp();
 realExceptionService = App.__container__.lookup('service:servicename');