Handle ansible-playbook failure for config-download
Handle ansible-playbook failure for config-download

Previously, the task was only failed if something unexpected happened.
This change checks the return code from ansible-playbook and will send a
failure message out on the zaqar queue for clients to consume.

Change-Id: I12f0b2d4416cf5aa36743326154ccb559a77376b

openstack/tripleo-common,openstack/tripleo-common