Fix #5 - Added devDependency badge

Author: joshghent

README.md

@@ -1,4 +1,4 @@
-# Query-Stringifier [![Build Status](https://travis-ci.org/joshghent/query-stringifier.svg?branch=master)](https://travis-ci.org/joshghent/query-stringifier) [![npm version](https://badge.fury.io/js/query-stringifier.svg)](https://badge.fury.io/js/query-stringifier)
+# Query-Stringifier [![Build Status](https://travis-ci.org/joshghent/query-stringifier.svg?branch=master)](https://travis-ci.org/joshghent/query-stringifier) [![npm version](https://badge.fury.io/js/query-stringifier.svg)](https://badge.fury.io/js/query-stringifier) [![devDependencies](https://david-dm.org/joshghent/query-stringifier.svg)]
 A small library for build query strings
 
 ## Install
@@ -33,4 +33,4 @@ qs.parse('?food=pizza&bar=chocolate');
 ```
 
 ## Issues?
-Go [here](https://github.com/joshghent/query-stringifier/issues)
+Go [here](https://github.com/joshghent/query-stringifier/issues)