Image extending tozd/sympa image to configure it for Cloyne.

It contains hard-coded values used at the Cloyne deployment.

Note: Depending on the name of the mailing list being added, you may have to edit /srv/sympa/etc/shared/sympa_transport to prevent it from bouncing as "unknown user". Afterwards, restart postfix:

`--# docker exec -ti mail script -q -c "/bin/bash" /dev/null
root@mail:# postfix reload