Add Gitter badge

Author: gitter-badger

README.md

@@ -1,5 +1,7 @@
 ## Angular-CLI
 
+[![Join the chat at https://gitter.im/angular/angular-cli](https://badges.gitter.im/angular/angular-cli.svg)](https://gitter.im/angular/angular-cli?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+
 [![Build Status][travis-badge]][travis-badge-url]
 [![Dependency Status][david-badge]][david-badge-url]
 [![devDependency Status][david-dev-badge]][david-dev-badge-url]