move ServiceClass and ServiceResource before Slice
diff --git a/planetstack/core/models/__init__.py b/planetstack/core/models/__init__.py
index d922802..cb5ff7d 100644
--- a/planetstack/core/models/__init__.py
+++ b/planetstack/core/models/__init__.py
@@ -7,8 +7,9 @@
 from .user import User
 from .role import Role
 from .node import Node
+from .serviceclass import ServiceClass
+from .serviceresource import ServiceResource
 from .slice import Slice
 from .slice import SliceMembership
 from .sliver import Sliver
-from .serviceclass import ServiceClass
-from .serviceresource import ServiceResource
+