Fix swiftclient mocks
Fix swiftclient mocks

In particular, stop mocking out some internal details like
swiftclient.client.Connection._retry

Change-Id: If118b9656ae1e87139c0d48dcc97c1daee948a85
Related-Change: I62cc037493af87373a75e37e2d9f33b8aedf9889
Related-Bug: 1556059

openstack/glance_store,openstack/glance_store