Updated Predis to work with 1.*, not 0.8

I'm not sure if you'll have any use for this or be interested in any of the changes, but these are changes I made to get SncRedisBundle working with Predis 1.0 -- take them or leave them. Tests look to be passing (with two failures that were present before the changes I've made.)
Actually this whole class doesn't make much sense to begin with, along with the `RandomDistributionStrategy` being used internally. What kind of cluster is it when keys land on random nodes? :-)