Statically configure borgbackup with sane defaults.
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This module implements the `borgbackup` backend and implements sane defaults 
for backup management through `borgbackup` for members of the clan.

Configure target machines where the backups should be sent to through `targets`.

Configure machines that should be backuped either through `includeMachines`
which will exclusively add the included machines to be backuped, or through 
`excludeMachines`, which will add every machine except the excluded machine to the backup.