Add a Gitter chat badge to README.md (#598)

* Add Gitter badge

* Update README.md

README.md

@@ -1,5 +1,6 @@
 # Algo VPN
 
+[![Join the chat at https://gitter.im/trailofbits/algo-support](https://badges.gitter.im/trailofbits/algo-support.svg)](https://gitter.im/trailofbits/algo-support?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 [![TravisCI Status](https://api.travis-ci.org/trailofbits/algo.svg?branch=master)](https://travis-ci.org/trailofbits/algo)
 [![Slack Status](https://empireslacking.herokuapp.com/badge.svg)](https://empireslacking.herokuapp.com)
 [![Twitter](https://img.shields.io/twitter/url/https/twitter.com/fold_left.svg?style=social&label=Follow%20%40AlgoVPN)](https://twitter.com/AlgoVPN)