In addition to `linux-upstart` and `linux-systemd`, I think this one
might be very useful too.

The script is based on [this script](https://git.devuan.org/fredg/stuffs/blob/master/caddy/init.d/caddy)
by @fredg, found via [Installation du serveur Caddy sous Devuan · Frédéric Galusik](http://galusik.xyz/installation-caddy-server-devuan/#démon:d7570338f345f168f3c50f22e7f8c47c).
I have modified it into an extended version myself, since I had the need for this.