TrivialFix: Using assertIsNone() instead of assertEqual(None)

Change-Id: I1e3c101b6d8f21bbf98c98f5451334cc1b524d5b

keystoneclient/tests/unit/v2_0/test_services.py

@@ -98,7 +98,7 @@ class ServiceTests(utils.ClientTestCase):
         self.assertIsInstance(service, services.Service)
         self.assertEqual(service.id, service_id)
         self.assertEqual(service.name, req_body['OS-KSADM:service']['name'])
-        self.assertEqual(service.description, None)
+        self.assertIsNone(service.description)
         self.assertRequestBodyIs(json=req_body)
 
     def test_delete(self):