Add gitter link to README

Author: ianfixes

Diff for: README.md

@@ -1,5 +1,8 @@
 
-# ArduinoCI Ruby gem (`arduino_ci`) [![Gem Version](https://badge.fury.io/rb/arduino_ci.svg)](https://rubygems.org/gems/arduino_ci) [![Documentation](http://img.shields.io/badge/docs-rdoc.info-blue.svg)](http://www.rubydoc.info/gems/arduino_ci/0.3.0)
+# ArduinoCI Ruby gem (`arduino_ci`) 
+[![Gem Version](https://badge.fury.io/rb/arduino_ci.svg)](https://rubygems.org/gems/arduino_ci) 
+[![Documentation](http://img.shields.io/badge/docs-rdoc.info-blue.svg)](http://www.rubydoc.info/gems/arduino_ci/0.3.0)
+[![Gitter](https://badges.gitter.im/Arduino-CI/arduino_ci.svg)](https://gitter.im/Arduino-CI/arduino_ci?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)
 
 You want to run tests on your Arduino library (bonus: without hardware present), but the IDE doesn't support that.  Arduino CI provides that ability.