attempt to fix test again

tests/test_generics.py

@@ -530,7 +530,7 @@ def test_dynamic_serializer_form_in_browsable_api(self):
         view = DynamicSerializerView.as_view()
         request = factory.get('/')
         response = view(request).render()
-        assert response is 'field_b'
+        assert 'field_b' in response
         assert 'field_a' not in response