docs(readme): add Greenkeeper badge

README.md

@@ -1,6 +1,6 @@
 # rosid-handler-js
 
-[![Travis Build Status](https://travis-ci.org/electerious/rosid-handler-js.svg?branch=master)](https://travis-ci.org/electerious/rosid-handler-js) [![AppVeyor Status](https://ci.appveyor.com/api/projects/status/dbl3yks4dh155gqb?svg=true)](https://ci.appveyor.com/project/electerious/rosid-handler-js) [![Coverage Status](https://coveralls.io/repos/github/electerious/rosid-handler-js/badge.svg?branch=master)](https://coveralls.io/github/electerious/rosid-handler-js?branch=master) [![Dependencies](https://david-dm.org/electerious/rosid-handler-js.svg)](https://david-dm.org/electerious/rosid-handler-js#info=dependencies)
+[![Travis Build Status](https://travis-ci.org/electerious/rosid-handler-js.svg?branch=master)](https://travis-ci.org/electerious/rosid-handler-js) [![AppVeyor Status](https://ci.appveyor.com/api/projects/status/dbl3yks4dh155gqb?svg=true)](https://ci.appveyor.com/project/electerious/rosid-handler-js) [![Coverage Status](https://coveralls.io/repos/github/electerious/rosid-handler-js/badge.svg?branch=master)](https://coveralls.io/github/electerious/rosid-handler-js?branch=master) [![Dependencies](https://david-dm.org/electerious/rosid-handler-js.svg)](https://david-dm.org/electerious/rosid-handler-js#info=dependencies) [![Greenkeeper badge](https://badges.greenkeeper.io/electerious/rosid-handler-js.svg)](https://greenkeeper.io/)
 
 A function that loads a JS file and transforms, bundles and compresses its content.