Updated openstack/openstack
Project: openstack/keystone  37c6766741e20f020e1980a0d579d9dc45310731

Merge remote-tracking branch 'remotes/origin/feature/hierarchical-multitenancy' into HEAD

This merge commit collapses the feature/hierarchical-multitenancy branch into
master.

Change-Id: I8505e4efc713f1c99c7cd747e1559c0fe6107181