Support for django 1.7

* django-nose version updated to 1.2 (instead of forked version used previously)
* Called setup() before executing the tests (https://docs.djangoproject.com/en/dev/releases/1.7/#standalone-scripts)
* Running migrate instead of syncdb in case of django version > 1.7
lol
Actually the tests were failing on django 1.7. There was a complain about the class TestModel being defined twice.
I don't quite understand what was going on since the two TestModel classes were defined in different scopes.

Renaming one of them fixed the problem but still I want to know why it was breaking. Any clues?