chore: Added Gitter badge

Closes angular#884

Author: gitter-badger

README.md

@@ -1,6 +1,7 @@
-Angular [![Build Status](https://travis-ci.org/angular/angular.svg?branch=master)](https://travis-ci.org/angular/angular)
+Angular [![Build Status](https://travis-ci.org/angular/angular.svg?branch=master)](https://travis-ci.org/angular/angular) [![Join the chat at https://gitter.im/angular/angular](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/angular/angular?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 =========
 
+
 This is the repository for the upcoming 2.0 version. If you're looking for the current official version of Angular you
 should go to [angular/angular.js](https://github.com/angular/angular.js)