Use IPAddress instead of Name for ReplicaSet

[goncalopereira]

I had a problem recently with a DNS failure which meant the replicaset broke as there is no way to override the replicaset list as seen here: https://github.com/edelight/chef-mongodb/blob/bd92ed176af2efdaefb1016b732a239d3e199be6/libraries/mongodb.rb

your fix allows to use IP Addresses with MongoS but not regular ReplicaSets - any suggestions?

I saw another post saying that a CNAME would be easier to switch to a node but in my scenario with Discovery and Autoscalling it is easier just to add a brand new one to the replicaset.