Add dependency badge

Author: garyb

README.md

@@ -2,6 +2,7 @@
 
 [![Latest release](http://img.shields.io/bower/v/purescript-argonaut-core.svg)](https://github.com/purescript-contrib/purescript-argonaut-core/releases)
 [![Build Status](https://travis-ci.org/purescript-contrib/purescript-argonaut-core.svg?branch=master)](https://travis-ci.org/purescript-contrib/purescript-argonaut-core)
+[![Dependency Status](https://www.versioneye.com/user/projects/563a993c1d47d40019000870/badge.svg?style=flat)](https://www.versioneye.com/user/projects/563a993c1d47d40019000870)
 [![Maintainer: slamdata](https://img.shields.io/badge/maintainer-slamdata-lightgrey.svg)](http://github.com/slamdata)
 
 Core part of `purescript-argonaut` that contains basic types for `Json`, folds over them, tests, printer and parser.