Preparing the field for this patch:
https://review.openstack.org/#/c/205282/2
The client.cinder key needs to have write permission to the glance pool
in order to complete the snapshot process.
Change-Id: I90c6aa056b99944aa558783f3f81d06f918f3e26
Signed-off-by: Sébastien Han <seb@redhat.com>