Run worldump if tempest fails

If things go wrong during devstack's setup we run worlddump. Lets run
the same thing if something in tempest goes wrong, so we can collect
more data.

This will allow us to do things like trigger guru meditation reports in
nova-compute to see what it is doing (if it hangs etc.)

Change-Id: I035fe8e3333034e44b403ed0f986220ab5b0e57a

devstack-vm-gate-wrap.sh

@@ -510,6 +510,8 @@ RETVAL=$GATE_RETVAL
 if [ $GATE_RETVAL -ne 0 ]; then
     echo "ERROR: the main setup script run by this job failed - exit code: $GATE_RETVAL"
     echo "    please look at the relevant log files to determine the root cause"
+    echo "Running devstack worlddump.py"
+    sudo $BASE/new/devstack/tools/worlddump.py -d $BASE/logs
 fi
 
 # Run post test hook if we have one