Add bountysource badge

README.md

@@ -1,6 +1,7 @@
 # converse.js
 
 [![Travis](https://api.travis-ci.org/jcbrand/converse.js.png?branch=master)](https://travis-ci.org/jcbrand/converse.js)
+[![Bountysource](https://img.shields.io/bountysource/team/converse.js/activity.svg?maxAge=2592000)](https://www.bountysource.com/teams/converse.js/issues?tracker_ids=194169)
 
 [Converse.js](https://conversejs.org) is a web based [XMPP/Jabber](http://xmpp.org) instant messaging client.