auto fail over support

[tolitius]

first off, thank you for creating and maintaining this library!

I see #134 and #76 and also that spec takes a single host

Looking to make sure a client can auto fail over when redis promotes a new host to master:

MasterReplica connector from lettuce takes a sequence of URIs that it internally iterates over to make sure "the next" available node is used:

I don't think carmine is there yet: i.e. would not support an auto fail over. But instead of assuming it, I'd like to confirm to make sure I did not miss anything.