ExecStopPost should allow us to clean up (docker kill + docker rm)
even if the ExecStart (docker run ..) command failed, and not just after
a graceful service stop was initiated.

Source: https://www.freedesktop.org/software/systemd/man/systemd.service.html#ExecStopPost=

It seems like it doesn't cause any issues for any of these services.

Initial attempt. Seems to work fine.

Only tested on debian amd64 so far