Added NPM badge [skip ci]

Author: brianreavis

README.md

@@ -1,5 +1,6 @@
 # selectize.js
 
+[![NPM version](http://img.shields.io/npm/v/selectize.svg?style=flat)](https://www.npmjs.org/package/selectize)
 ![Bower version](http://img.shields.io/bower/v/selectize.svg?style=flat)
 [![Build Status](http://img.shields.io/travis/brianreavis/selectize.js/master.svg?style=flat)](https://travis-ci.org/brianreavis/selectize.js)
 [![Coverage Status](http://img.shields.io/coveralls/brianreavis/selectize.js/master.svg?style=flat)](https://coveralls.io/r/brianreavis/selectize.js)