It happens somewhat regularly that pk-web stops syncing commits to
github, and sending e-mails about it, because any docker run process
seems to get stucked. Invariably, restarting the docker service
(systemctl restart docker), seems to fix the problem.
This change adds a timeout mechanism for functions running a docker run
exec, so that after the timeout, we get notified by e-mail about what
function is blocked.
Change-Id: I16bd4f5abc7864ceb176a0e69c5300165194b18f