adds npm badge

README.md

@@ -2,6 +2,7 @@
 
 ![An image that shows if build is passing](https://travis-ci.org/egeozcan/ppipe.svg?branch=master "Build Status")
 [![Coverage Status](https://coveralls.io/repos/github/egeozcan/ppipe/badge.svg?branch=master)](https://coveralls.io/github/egeozcan/ppipe?branch=master)
+[![npm version](https://badge.fury.io/js/ppipe.svg)](https://badge.fury.io/js/ppipe)
 
 pipes values through functions, an alternative to using the [proposed pipe operator](https://github.com/mindeavor/es-pipeline-operator) ( |> ) for ES.