[cli-ref] Update python-ceilometerclient to 2.7.0
[cli-ref] Update python-ceilometerclient to 2.7.0

Regenerated with current doc-tools.

Change-Id: I0c01295cb8fb5b28a74d6603093642df3dc69feb

openstack/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals