Updated openstack/openstack
Project: openstack/keystone  96b1326bcf9a650acf98a9d7f1835133a58b8c86

sys.exit mock cleanup

The base testcase didn't need to keep a reference to the sys.exit
mockpatch fixture.

Also, added a unit test for calling sys.exit() since there wasn't
one.

Change-Id: Ifa2e6c89dc556ed09623805e618a95744cc8c97f