Remove obj_relationships from objects

In Liberty, we converted to using the manifest-based class
action and backport methods, which no longer rely on these
object relationship maps. They provide a full manifest of
client-side versions with each call, which is far more
robust than us trying to hand-edit these mappings (which
we get incorrect a lot).

Since we're now in Mitaka, we can drop compatibility with
clients that don't make the version-manifest calls. Those
have also been deprecated in oslo.versionedobjects.

Change-Id: Iea8b6348e3b01aaa335ec5408f07826f1e758d20

nova/objects/aggregate.py

@@ -163,11 +163,6 @@ class AggregateList(base.ObjectListBase, base.NovaObject):
         'objects': fields.ListOfObjectsField('Aggregate'),
         }
 
-    # NOTE(danms): Aggregate was at 1.1 before we added this
-    obj_relationships = {
-        'objects': [('1.0', '1.1'), ('1.1', '1.1'), ('1.2', '1.1')],
-        }
-
     @classmethod
     def _filter_db_aggregates(cls, db_aggregates, hosts):
         if not isinstance(hosts, set):