* fix( DjangoListField ): test that default functionality should resolve/call queryset at view time, first attempt at solution
* fix( DjangoListField ): DjangoListField defines get_manager just like DjangoConnectionField for a better variable name default_manager instead of default_queryset
* fix: apply specific black formatting
* Reset the global registry after each test (teardown)
* Create a settings fixtures that returns graphene_settings and resets
the graphene_settings after use (teardown)
* Convert test_mutation tests from unittests.TestCase to pytest
* Convert test_mutation PetType to a pet_type fixtures that reregisters
the type
