Zuul: add file extension to playbook path
Zuul: add file extension to playbook path

Zuul now supports including the file extension on the playbook path
and omitting the extension is now deprecrated.  Update references
to include the extension.

Change-Id: Ib6213593f87b6fce2059e01123348d4951ecccd6

openstack/barbican,openstack/barbican