Update run as worker to pass SIGTERM correctly to subprocess

The reason we weren't gracefully shutting down before is that bash
won't forward SIGTERMs to processes that are running in the foreground.
Merge branch 'master' of github.com:Clever/oplog-dump into use-gearcmd

Conflicts:
	run_as_worker.sh
Merge pull request #7 from Clever/use-gearcmd

Update run as worker to pass SIGTERM correctly to subprocess