added codeclimate badge

README.md

@@ -35,6 +35,8 @@ The vis.js library was initially developed by [Almende B.V](http://almende.com).
 [![GitHub issues](https://img.shields.io/github/issues/almende/vis.svg)](https://github.com/almende/vis/issues)
 [![Pending Pull-Requests](http://githubbadges.herokuapp.com/almende/vis/pulls.svg)](https://github.com/almende/vis/pulls)
 
+[![Code Climate](https://codeclimate.com/github/almende/vis/badges/gpa.svg)](https://codeclimate.com/github/almende/vis)
+
 ## Install
 
 Install via npm: