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: I50aad0174b72a2c65f6c92b7abf222f0a363b509

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