Currently the default Sensu check defined in docker/services/sensu-client.yaml
reports only first unhealthy container. This patch changes the check output
to contain list of all unhealthy containers.
Change-Id: I0a934367ef22984d9091d160ec7105092edc8149
Closes-Bug: #
1720972
(cherry picked from commit
9b016c9f3fbe9552497737974b9928d1dff4d299)