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: Ia726109e485be3eb3d504429b2a7ca3ebe145e56

openstack/oslo.db,openstack/oslo.db