README: Add better NPM stats image

Author: kyledrake

README.md

@@ -2,7 +2,7 @@
 
 [![Build Status](https://travis-ci.org/bitcoinjs/bitcoinjs-lib.png?branch=master)](https://travis-ci.org/bitcoinjs/bitcoinjs-lib) [![Coverage Status](https://coveralls.io/repos/bitcoinjs/bitcoinjs-lib/badge.png)](https://coveralls.io/r/bitcoinjs/bitcoinjs-lib)
 
-[![NPM](https://nodei.co/npm-dl/bitcoinjs-lib.png)](https://nodei.co/npm/bitcoinjs-lib/)
+[![NPM](https://nodei.co/npm/bitcoinjs-lib.png)](https://nodei.co/npm/bitcoinjs-lib/)
 
 [![Browser Support](https://ci.testling.com/bitcoinjs/bitcoinjs-lib.png)](https://ci.testling.com/bitcoinjs/bitcoinjs-lib)