Replaced gitter with discourse and SO

README.md

@@ -1,7 +1,8 @@
 # drone-slack
 
 [![Build Status](http://beta.drone.io/api/badges/drone-plugins/drone-slack/status.svg)](http://beta.drone.io/drone-plugins/drone-slack)
-[![Join the chat at https://gitter.im/drone/drone](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/drone/drone)
+[![Join the discussion at https://discourse.drone.io](https://img.shields.io/badge/discourse-forum-orange.svg)](https://discourse.drone.io)
+[![Drone questions at https://stackoverflow.com](https://img.shields.io/badge/drone-stackoverflow-orange.svg)](https://stackoverflow.com/questions/tagged/drone.io)
 [![Go Doc](https://godoc.org/github.com/drone-plugins/drone-slack?status.svg)](http://godoc.org/github.com/drone-plugins/drone-slack)
 [![Go Report](https://goreportcard.com/badge/github.com/drone-plugins/drone-slack)](https://goreportcard.com/report/github.com/drone-plugins/drone-slack)
 [![](https://images.microbadger.com/badges/image/plugins/slack.svg)](https://microbadger.com/images/plugins/slack "Get your own image badge on microbadger.com")