Relay check improved

[bernatfp]

Addresses #22

Specifically, we made the following changes:

1. Improved exception handling to avoid crashing when a relay does not respond, and report those cases as 'unknown'
2. Moved the current reporting mode to a --detailed flag
3. Added a less verbose, default mode
4. Added a --pubkey mode to inspect just one key in detail
5. Report the entire public key in the reports