Throttle tripleo-cd.sh

Prevent tripleo-cd.sh from spamming IRC channels when it encounters an
error that happens early in the devtest_overcloud.sh story by throttling
it to running at most once every 10 minutes.

Change-Id: I703eb5ca5525eff97a6925cfe2c585f8908798c5
Merge "Throttle tripleo-cd.sh"