Update glance/opensatck/common from oslo Part 3

Update from oslo:
- glance/openstack/common/fixture
- glance/openstack/common/test.py

And update openstack-common.conf

Oslo commit: 764ad35e89d20008bf48d17e4129cfce5b717a6c

Change-Id: Ic20666521e2e3d4241035bcb07fa7da3a4a5bf38