add badge.fury.io npm version badge

README.md

@@ -3,6 +3,7 @@ Yet Another Plugin Server
 
 [![Build Status](https://travis-ci.org/brettlangdon/yaps.png?branch=master)](https://travis-ci.org/brettlangdon/yaps)
 [![Coverage Status](https://coveralls.io/repos/brettlangdon/yaps/badge.png?branch=master)](https://coveralls.io/r/brettlangdon/yaps?branch=master)
+[![NPM version](https://badge.fury.io/js/yaps.png)](http://badge.fury.io/js/yaps)
 
 YAPS is plugin based HTTP server that gets out of your way and lets you do what you need to do.