Remove mox from tests/unit/objects/test_aggregate.py
Remove mox from tests/unit/objects/test_aggregate.py

This change replaces use of mox with mock in
tests/unit/objects/test_aggregate.py

Change-Id: I010aada6d6317d90310738d6fa3e6985ff0e0a53
Implements: blueprint remove-mox-newton

mahak/nova,rajalokan/nova,rahulunair/nova,openstack/nova,hanlind/nova,gooddata/openstack-nova,vmturbo/nova,sebrandon1/nova,Juniper/nova,mahak/nova,jianghuaw/nova,rajalokan/nova,phenoxim/nova,openstack/nova,mikalstill/nova,vmturbo/nova,mahak/nova,jianghuaw/nova,jianghuaw/nova,mikalstill/nova,rahulunair/nova,mikalstill/nova,klmitch/nova,cloudbase/nova,alaski/nova,gooddata/openstack-nova,klmitch/nova,vmturbo/nova,klmitch/nova,gooddata/openstack-nova,Juniper/nova,Juniper/nova,rajalokan/nova,hanlind/nova,hanlind/nova,rahulunair/nova,cloudbase/nova,gooddata/openstack-nova,vmturbo/nova,sebrandon1/nova,rajalokan/nova,klmitch/nova,openstack/nova,alaski/nova,phenoxim/nova,sebrandon1/nova,Juniper/nova,jianghuaw/nova,cloudbase/nova