add openstack theme

Change-Id: Iae4c09ee950fa3617c6fc2b990bc26d0a50367ec
Signed-off-by: Doug Hellmann <doug.hellmann@dreamhost.com>
Reviewed-on: https://review.openstack.org/32628
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Approved: James E. Blair <corvus@inaugust.com>
Reviewed-by: James E. Blair <corvus@inaugust.com>
Tested-by: Jenkins