Auto merge of #4962 - xcambar:travis_yml_node_version, r=stefanpenner

Declares node.js version as documented by Travis

As per http://docs.travis-ci.com/user/languages/javascript-with-nodejs/#Choosing-Node-versions-to-test-against

.travis.yml

@@ -1,15 +1,15 @@
 sudo: false
-env:
-  - NODE_VERSION=0.10
-  - NODE_VERSION=0.12
-  - NODE_VERSION=iojs
+language: node_js
+node_js:
+  - "0.10"
+  - "0.12"
+  - "iojs"
 
 os:
   - linux
 script: npm run-script test-all:cover
 before_install:
   - test $TRAVIS_OS_NAME = "osx" && brew update && brew install nvm && source $(brew --prefix nvm)/nvm.sh && brew install phantomjs || test $TRAVIS_OS_NAME = "linux"
-  - nvm install $NODE_VERSION
   - npm config set spin false
 install:
   - node --version