Enable panko API health check

This patch enables health check execution for Panko API
docker container.

Change-Id: I8e4315465faf9b246a0086ed5c24f1fbbbff6c1b
Depends-On: I1109909189b2c14c89913e217e2eb3b520897596

docker/services/panko-api.yaml

@@ -135,6 +135,8 @@ outputs:
             net: host
             privileged: false
             restart: always
+            healthcheck:
+              test: /openstack/healthcheck
             volumes:
               list_concat:
                 - {get_attr: [ContainersCommon, volumes]}