Travis image, remove 0.6 test

.travis.yml

@@ -3,4 +3,3 @@ node_js:
   - "0.11"
   - "0.10"
   - "0.8"
-  - "0.6"

README.md

@@ -1,5 +1,6 @@
 # bitcoinjs-lib
 
+[![Build Status](https://travis-ci.org/bitcoinjs/bitcoinjs-lib.png)](https://travis-ci.org/bitcoinjs/bitcoinjs-lib)
 [![browser support](https://ci.testling.com/bitcoinjs/bitcoinjs-lib.png)](https://ci.testling.com/bitcoinjs/bitcoinjs-lib)
 
 A pure JavaScript Bitcoin library for node.js and browsers. Backed by (slowly improving) testing, proven by over a million wallet users. The backbone for almost all Bitcoin web wallets in production today.