Check relevant logging mechanism in the gate

Avoids errors about missing journalctl on Ubuntu and missing upstart on
redhat bases.

Closes-Bug: 1554724

Change-Id: I80bb55688398df85f9020d5cfe5dda757fc5a0ef

tools/deploy_aio.sh

@@ -32,8 +32,11 @@ function check_failure {
         docker logs --tail all ${failed}
     done
 
-    journalctl --no-pager -u docker.service
-    cat /var/log/upstart/docker.log
+    if [[ -x "$(command -v journalctl)" ]]; then
+        journalctl --no-pager -u docker.service
+    else
+        cat /var/log/upstart/docker.log
+    fi
 
     nova service-list
     neutron agent-list