Add integration tests for record listing with pretender

I don't think the preceding hyphen is necessary.  This is how I did it in the current v0.4.0 version: https://github.com/dustinfarris/ember-django-adapter/blob/master/app/adapters/django.js#L4 which corresponds to the django serializer (identified by filename) here: https://github.com/dustinfarris/ember-django-adapter/tree/master/app/serializers

Right now in the version-1.0 branch we just have an "application" adapter and an "application" serializer which means this line isn't necessary because Ember will choose those by default anyway.  This may not be the right way to go, though, and perhaps we should continue doing it the way I did it in master, which would be to move `app/serializers/application.js` to `app/serializers/drf.js` and then change this line to `defaultSerializer: 'drf'`