Merge pull request #6 from Level/greenkeeper/initial

Add Greenkeeper badge 🌴

Author: ralphtheninja

.travis.yml

@@ -6,6 +6,7 @@ node_js:
 branches:
   only:
     - master
+    - /^greenkeeper/.*$/
 notifications:
   email:
     - r@va.gg

README.md

@@ -5,7 +5,7 @@
 
 **Error module for [LevelUP](https://github.com/rvagg/node-levelup)**
 
-[![Build Status](https://travis-ci.org/Level/errors.png)](https://travis-ci.org/Level/errors)
+[![Build Status](https://travis-ci.org/Level/errors.png)](https://travis-ci.org/Level/errors) [![Greenkeeper badge](https://badges.greenkeeper.io/Level/errors.svg)](https://greenkeeper.io/)
 
 ## Usage