Key management endpoint

[technosophos]

Do we want to provide an endpoint for fetching the public keys that Bindle knows about? /cc @radu-matei

[technosophos]

I think that for right now, we have decided not to do this on Bindle itself. Bindle will have a keyring file located in a well-documented location (See #87). So we would just leave it to the user or to other tooling to manage that file for now.

[thomastaylor312]

Between the new CLI functionality for managing keychains and the proposal at #300 that supersedes this, I think we can go ahead ad close it