Initial configuration capability

[Libbum]

Currently we set up things like the notification system (#62) in plain text in the config file. It would be better if some of this info was stored in the database encrypted.

Clap can enable sub-commands, wherein we can run a CLI module to enter in username/password details directly for example.

Consideration on whether this is needed if we have a running Admin backend (#16) should also be investigated.

[Libbum]

Another thought: Users will not necessarily need to use the development tools to use Oration once #57 is sorted, so the requirement to run the diesel migrations should be folded into this setup process.