Symbiosis: monit: Use systemd timer to launch instead of cron
Imported from https://www.github.com/BytemarkHosting/symbiosis/issues/55
This requires a .timer as well as a .service file](https://wiki.archlinux.org/index.php/Systemd/Timers). It also means that sysvinit isn't really supported, unless a check is put in place to remove the cron job or otherwise disable it.