Use pytest as our test runner for better parallelism

Also rewrote some asset tests to be in the pytest style. May do some more. Some warnings cleaned up in the process.

versioning/tests/test_versioning.py

@@ -305,6 +305,3 @@ class TestVersioningViews(TestCase):
         response = self.client.get(request_url, follow=True)
         self.assertContains(response, "Test Person")
         self.assertEqual(response.status_code, 200)
-
-
-# Functional Tests