Bring admin client methods to fs2-kafka.

[cmcmteixeira]

Adds to fs2-kafka the missing methods present in the underlying java admin client.

• made a conscious decision to stop the user from being able to provide the "xxxOptions" object. This was to make things consistent with the current methods where this object(s) are never exposed. I've also didn't allow the timeout to be specifiable as it wasn't a config for any of the other methods
• tests still need to be added