Feature/cronjob
This issue was automatically migrated from github issue https://github.com/TheTorProject/ooni-probe/issues/276.
This implements the feature described in this ticket: https://trac.torproject.org/projects/tor/ticket/10734.
We currently don't check for the exit code of ooniprobe, so we don't handle rescheduling runs of ooniprobe when the network is down.