Add support for io.js

Unfortunately version 1.6.2 of nan appears to be broken
(nodejs/nan#265) so we pin to 1.5.0 until 1.6.2
comes out

.travis.yml

@@ -4,6 +4,11 @@ os:
 - linux
 - osx
 
+env:
+  matrix:
+    - NODE_VERSION="0.10"
+    - NODE_VERSION="iojs"
+
 # What we'll be using to compile
 compiler:
 - gcc
@@ -30,8 +35,8 @@ install:
 - rm -rf ~/.nvm/
 - git clone --depth 1 https://github.com/creationix/nvm.git ~/.nvm
 - source ~/.nvm/nvm.sh
-- nvm install 0.10
-- nvm use 0.10
+- nvm install $NODE_VERSION
+- nvm use $NODE_VERSION
 
 # put local node-pre-gyp on PATH
 - export PATH=./node_modules/.bin/:$PATH

package.json

@@ -6,8 +6,8 @@
   "main": "index.js",
   "gypfile": true,
   "dependencies": {
-    "nan": "^1.5.0",
-    "node-pre-gyp": "^0.6.1"
+    "nan": "<2.0.0 >1.6.2 || 1.5.0",
+    "node-pre-gyp": "^0.6.2"
   },
   "devDependencies": {},
   "bundledDependencies": [
@@ -30,4 +30,4 @@
   },
   "author": "ForbesLindesay",
   "license": "MIT"
-}
+}