add guble

README.md

@@ -592,6 +592,7 @@ See [go-hardware](https://github.com/rakyll/go-hardware) for a comprehensive lis
 * [go-nsq](https://github.com/nsqio/go-nsq) - the official Go package for NSQ
 * [gopush-cluster](https://github.com/Terry-Mao/gopush-cluster) - gopush-cluster is a go push server cluster.
 * [gorush](https://github.com/appleboy/gorush) - A push notification server using [APNs2](https://github.com/sideshow/apns2) and google [GCM](https://github.com/google/go-gcm).
+* [guble](https://github.com/smancke/guble) - A messaging server using push notifications (Google Firebase Cloud Messaging, Apple Push Notification services, SMS) as well as websockets, a REST API, featuring distributed operation and message-persistence.
 * [machinery](https://github.com/RichardKnop/machinery) - An asynchronous task queue/job queue based on distributed message passing.
 * [mangos](https://github.com/go-mangos/mangos) - Pure go implementation of the Nanomsg ("Scalable Protocols") with transport interoperability.
 * [NATS Go Client](https://github.com/nats-io/nats) - A lightweight and high performance publish-subscribe and distributed queueing messaging system - this is the Go library.