Update README.md

Author: sksamuel

README.md

@@ -7,6 +7,8 @@ scoverage is available for sbt, maven, and gradle.
 [![Build Status](https://travis-ci.org/scoverage/scalac-scoverage-plugin.svg?branch=master)](https://travis-ci.org/scoverage/scalac-scoverage-plugin)
 [![License](http://img.shields.io/:license-Apache%202-red.svg)](http://www.apache.org/licenses/LICENSE-2.0.txt)
 
+[![Join the chat at https://gitter.im/scoverage/scoverage](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/scoverage/scoverage?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+
 Join the [scoverage](http://groups.google.com/group/scala-code-coverage-tool)
 google group for help, bug reports, feature requests, and general
 discussion on scoverage.