Behavior

This card implements (most of) the server side scripting necessary for automated backups
It provides a bin/db/backup script that:
- produces encrypted backups of a psql dump and the docker volumes of the db and signal keystore
- encrypts those backups to @margot and @aguestuser
It does not:
- scp those backups onto a target machine
- provide any scripting for restoring from backups
- do anything via ansible
- create any new ssh keys for the host machine to use to access the backup target
All of the undone things are left for #40 (closed)
This increases the likelihood that we will backup manually more frequently by making it more easier, and tries to help #40 (closed) get done sooner

Side Effects

It also provides a lot of random scripts that it would have been nice to have on the server while investigating the outage that made us realize backups were a super duper urgent issue!