Add separate ACL/group for castellan
Add separate ACL/group for castellan

The Barbican team would like to move Castellan under Oslo. This
change would help setup a group that includes both oslo and
barbican cores to take care of castellan

http://lists.openstack.org/pipermail/openstack-dev/2017-March/114335.html
http://eavesdrop.openstack.org/meetings/barbican/2017/barbican.2017-03-20-20.00.txt

Depends-On: I571dc981a198fcde1a8bdf626ce159b860d452aa
Change-Id: I7928b922ad7a7519bf28041214ee50d3ca732a91

openstack-infra/project-config,openstack-infra/project-config