Update README.md

Author: dansabin

README.md

@@ -1,5 +1,6 @@
 [![view on npm](http://img.shields.io/npm/v/inline-email.svg)](https://www.npmjs.org/package/inline-email)
 [![npm module downloads](http://img.shields.io/npm/dt/inline-email.svg)](https://www.npmjs.com/package/inline-email)
+[![node](https://img.shields.io/node/v/inline-email.svg)](https://www.npmjs.org/package/inline-email)
 [![Build Status](https://travis-ci.org/freethinkingit/inline-email.svg?branch=master)](https://travis-ci.org/freethinkingit/inline-email)
 [![dependencies Status](https://david-dm.org/freethinkingit/inline-email/status.svg)](https://david-dm.org/freethinkingit/inline-email)