Updated openstack/openstack
Project: openstack-dev/devstack  52f13a4087ef8b49640053bebd6a5046d55c63fe

remove the trove exercise

The trove cli has been changed in an incompatible way. Exercises
are the requirements of projects to keep functioning, if they aren't
we should fast delete them.

Related-Bug: #1391840

Change-Id: I3b61194ff220525aed202c7f7851faa0be446646