CORD-1250 Update to new Service/Tenancy models

Change-Id: I37e73892af3d33163d60cc0095d9bf8368ec3e22
diff --git a/xos/attic/header.py b/xos/attic/header.py
index 33498dd..e3ab236 100644
--- a/xos/attic/header.py
+++ b/xos/attic/header.py
@@ -1,5 +1,5 @@
 from django.db import models
-from core.models import Service, XOSBase, Slice, Instance, Tenant, TenantWithContainer, Node, Image, User, Flavor
+from core.models import Service, XOSBase, Slice, Instance, ServiceInstance, Node, Image, User, Flavor
 from core.models.xosbase import StrippedCharField
 import os
 from django.db import models, transaction