* Add Meta.fields = '__all__' to serializer classes where required.
* Add explicit on_delete=models.CASCADE to ForeignKey fields.
* Use '.remote_field' and '.model' in preference to '.rel' and '.to' when inspecting model fields.
* Use new value_from_object in preference to internal _get_val_from_obj
* Added TEMPLATES setting to tests
* Remove deprecated view-string in URL conf
* Replace 'urls = ...' in test classes with override_settings('ROOT_URLCONF=...')
* Refactor UsingURLPatterns to use override_settings(ROOT_URLCONF=...) style
* Get model managers and names in a version-compatible manner.
* Apply override_settings to a TestCase, not a mixin class
* Use '.callback' property instead of private attributes when inspecting urlpatterns
* Pass 'user' to template explicitly
* Correct sorting of import statements.
* Remove unused TEMPLATE_LOADERS setting, in favor of TEMPLATES.
* Remove code style issue
* BaseFilter test requires a concrete model
* Resolve tox.ini issues
* Resolve isort differences between local and tox environments
* Get rid of runtests.py
* Moved test code from rest_framework/tests and rest_framework/runtests to tests
* Invoke py.test from setup.py
* Invoke py.test from Travis
* Invoke py.test from tox
* Changed setUpClass to be just plain setUp in test_permissions.py
* Updated contribution guideline to show how to invoke py.test
