[FEATURE REQUEST] adapters support for scalability

Like socketio or signalr, they provide serval adapters such as redis.
Hope neffos could provide the adapter interface. let users could add their own implemention;
And It would be great for builtin support serval great pubsub system like [redis](https://github.com/gomodule/redigo) and [nats](github.com/nats-io/nats-server)

Thanks again for the great library.