Cannot use duniter without duniter-keypair
As of email@example.com we cannot create a new module and just have
duniter as dependency. We must add
duniter-keypair because Duniter does not have a default keyring, but must have one to work.
We could create a default one if none is provided by a module, for example using https://github.com/davidbau/seedrandom to generate it randomly.
Of course the keyring will be different on each run, but that's the expected behavior: to have a persistent keyring, we must add a module doing this work like
duniter-keyring. But this is not mandatory for Duniter to work.