CORD-2865 get creator from subscriber object

Change-Id: I51bc8841ff1802949336849c79366cf10993ca4b
diff --git a/xos/synchronizer/model_policies/model_policy_vsgserviceinstance.py b/xos/synchronizer/model_policies/model_policy_vsgserviceinstance.py
index 050093f..6800e81 100644
--- a/xos/synchronizer/model_policies/model_policy_vsgserviceinstance.py
+++ b/xos/synchronizer/model_policies/model_policy_vsgserviceinstance.py
@@ -106,14 +106,17 @@
         assert (slice is not None)
         assert (node is not None)
         assert (desired_image is not None)
-        assert (service_instance.creator is not None)
         assert (node.site_deployment.deployment is not None)
         assert (desired_image is not None)
 
+        assert(service_instance.volt)
+        assert(service_instance.volt.subscriber)
+        assert(service_instance.volt.subscriber.creator)
+
         instance = Instance(slice=slice,
                             node=node,
                             image=desired_image,
-                            creator=service_instance.creator,
+                            creator=service_instance.volt.subscriber.creator,
                             deployment=node.site_deployment.deployment,
                             flavor=flavors[0],
                             isolation=slice.default_isolation,
diff --git a/xos/synchronizer/model_policies/test_model_policy_vsgserviceinstance.py b/xos/synchronizer/model_policies/test_model_policy_vsgserviceinstance.py
index 99cdd94..5dd860d 100644
--- a/xos/synchronizer/model_policies/test_model_policy_vsgserviceinstance.py
+++ b/xos/synchronizer/model_policies/test_model_policy_vsgserviceinstance.py
@@ -79,7 +79,7 @@
         self.policy = VSGServiceInstancePolicy()
         self.tenant = VSGServiceInstance()
         self.user = User(email="testadmin@test.org")
-        self.tenant = VSGServiceInstance(creator=self.user, id=1)
+        self.tenant = VSGServiceInstance(id=1)
         self.flavor = Flavor(name="m1.small")
         self.npt_ctag = NetworkParameterType(name="c_tag", id=1)
         self.npt_stag = NetworkParameterType(name="s_tag", id=2)
@@ -378,7 +378,6 @@
 
             # make sure Instance was created
             self.assertNotEqual(instance, None)
-            self.assertEqual(instance.creator.email, "testadmin@test.org")
             self.assertEqual(instance.image.name, "trusty-server-multi-nic")
             self.assertEqual(instance.flavor.name, "m1.small")
             self.assertEqual(instance.isolation, "vm")