Add travis build status to README.md

Author: joeferner

README.md

@@ -3,6 +3,8 @@
 HTTP Man In The Middle (MITM) Proxy written in node.js. Supports capturing and modifying the request and response data.
 
 [![](https://david-dm.org/joeferner/node-http-mitm-proxy.svg)](https://david-dm.org/joeferner/node-http-mitm-proxy)
+[![Build Status](https://travis-ci.org/joeferner/node-http-mitm-proxy.svg?branch=master)](https://travis-ci.org/joeferner/node-http-mitm-proxy)
+
 
 # Install