update gitter badge url

Author: achingbrain

README.md

@@ -1,6 +1,6 @@
 # Nodebot Workshop
 
-[![Build Status](https://travis-ci.org/tableflip/nodebot-workshop.svg?branch=master)](https://travis-ci.org/tableflip/nodebot-workshop) [![Dependency Status](https://david-dm.org/tableflip/nodebot-workshop.svg)](https://david-dm.org/tableflip/nodebot-workshop) [![Gitter](https://badges.gitter.im/Join Chat.svg)](https://gitter.im/tableflip/nodebot-workshop?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+[![Build Status](https://travis-ci.org/tableflip/nodebot-workshop.svg?branch=master)](https://travis-ci.org/tableflip/nodebot-workshop) [![Dependency Status](https://david-dm.org/tableflip/nodebot-workshop.svg)](https://david-dm.org/tableflip/nodebot-workshop) [![Gitter](https://badges.gitter.im/join_chat.svg)](https://gitter.im/tableflip/nodebot-workshop?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
 **A [nodeschool][1] workshop on how to get your Arduino alive with [rwaldron/johnny-five][2]**