Sync fixtures from oslo and use LockFixture

This commit adds fixture to openstack-common.conf to sync fixtures
from oslo. This patch also updates the location from which
LockFixture is used. It was originally in
tempest.openstack.common.lockutils but it was moved to the fixture
module.

Change-Id: Icffa613b92e059926b5394e9881ae0d8fe7fa910
Merge "Sync fixtures from oslo and use LockFixture"