CXX-385 Use trap to respond to test failures

I really don't think you need to kill anything here other than MO. We don't have the mongo shell in this repo, nor mongod or mongos. If there are any mongod or mongos processes those are being managed by MO, which I presume takes them down on its own when it is asked to terminate (double check this please). Similarly, we don't have buildlogger.py or smoke.py in the repo, so there is nothing to kill.

Same below.