Check how many texts have failed: #121
Check how many texts have failed: #121

If too many texts to a given number have failed, then stop resending the
text (i.e., prevent an infinite loop).  Note that I don't check whether
the failures have been on the same text or not, which is probably a
check we should add later on.

OpenTechStrategies/smoke-alarm-portal,OpenTechStrategies/smoke-alarm-portal,OpenTechStrategies/smoke-alarm-portal,OpenTechStrategies/smoke-alarm-portal