remove node v0.4.x support

.travis.yml

@@ -1,4 +1,6 @@
 language: node_js
 node_js:
-  - 0.4
-  - 0.6
+  - "0.6"
+  - "0.8"
+  - "0.10"
+  - "0.11"

Readme.md

@@ -1,4 +1,4 @@
-[![Build Status](https://secure.travis-ci.org/guyht/notp.png)](http://travis-ci.org/guyht/notp)
+[![Build Status](https://travis-ci.org/guyht/notp.svg)](https://travis-ci.org/guyht/notp)
 
 # Node One Time Password library
  Simple to use, fast, and with zero dependencies.  The Node One Time Password library is fully compliant with [HOTP](http://tools.ietf.org/html/rfc4226) (counter based one time passwords) and [TOTP](http://tools.ietf.org/html/rfc6238) (time based one time passwords).  It can be used in conjunction with the [Google Authenticator](http://code.google.com/p/google-authenticator/) which has free apps for iOS, Android and BlackBerry.

package.json

@@ -13,7 +13,7 @@
     "test": "expresso"
   },
   "engines": {
-    "node": ">= v0.4.10"
+    "node": ">= v0.6.0"
   },
   "dependencies": {},
   "devDependencies": {