docs(readme): re-arrange badges

Author: Amine Mouafik

README.md

@@ -1,11 +1,9 @@
-[![Build Status](https://travis-ci.org/continuous-software/node-payflow.svg?branch=master)](https://travis-ci.org/continuous-software/node-payflow)
+[![Build Status](https://travis-ci.org/continuous-software/node-payflow.svg?branch=master)](https://travis-ci.org/continuous-software/node-payflow) [![Greenkeeper badge](https://badges.greenkeeper.io/continuous-software/node-payflow.svg)](https://greenkeeper.io/)
 
 ![node-payflow](http://i.imgbox.com/0KUdCy3t.png)
 
 ## Installation ##
 
-[![Greenkeeper badge](https://badges.greenkeeper.io/continuous-software/node-payflow.svg)](https://greenkeeper.io/)
-
     $ npm install -s payflow
 
 ## Usage