Add unit test to validate PID files exist
Add unit test to validate PID files exist

This is a follow up to a previous commit, make sure the PID files
actually exist.

We only need this for initd scripts today.

Change-Id: Iedad736a9656aa04bc9b696051e421663061c0bb
Signed-off-by: Paul Belanger <e7139c8e6c4ea75cc1c287ce081b2dc0f3ab39ec@redhat.com>

openstack/ansible-role-nodepool,openstack/ansible-role-nodepool