ceph-builders: Adding python-openstackclient for xenial
ceph-builders: Adding python-openstackclient for xenial

To build the OS images, using a recent OS is a good idea therefore we
can easily grab python-openstackclient to do the image uploading.

We don't use glance here as we have issues with OVH to upload to the proper
region when using glance client.

redhat-cip/edeploy,enovance/edeploy,enovance/edeploy,enovance/edeploy,redhat-cip/edeploy,redhat-cip/edeploy,enovance/edeploy,redhat-cip/edeploy