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: I9f7cfb25cdd87b7431ec0297a97aa827eec31799

openstack/pyghmi,openstack/pyghmi,stackforge/pyghmi