Do lookups for user, project

This requires https://review.openstack.org/26323 in keystoneclient

Change-Id: I55bededbc20b5dcf2833c59eb2b6b069703d8a9a
Merge branch 'volume-keystone' into dt-test

Conflicts:
	openstackclient/volume/v1/volume.py

Change-Id: Iae0cc1c31e6683e6be7d7b08b5b561c5589ea132