MongoUri convict validator does not support replicaset format uri

[labajo]

Example:
mongodb://service-3:27017,service-2:27017,service-1:27017/gsm?replicaSet=service1

https://github.com/Telefonica/alfalfa/blob/master/example/config.js#L7-L14

[jmendiara]

Removing the "bug" label as the example is not part of the functionality itself