[FEATURE ember-testing-simple-setup]

Removes the need for most of the ceremony of setting up an application for
testing. The following examples are equivalent:

Ember 1.0.0 type testing setup:

```javascript App = Ember.Application.create(); App.setupForTesting(); 
App.injectTestHelpers();
```

New simple setup:

```javascript App = Ember.Application.create({testing: true});
```