Remove ember-data revision number

Since Ember Data 0.13 the API revision check has been removed.

You no longer need to provide the API revision number when defining your
store, see http://emberjs.com/blog/2013/05/28/ember-data-0-13.htmlhttp://emberjs.com/blog/2013/05/28/ember-data-0-13.html#toc_api-revision-removal