language: node_js
node_js:
  - 4
  - 5
before_script:
  - npm install -g grunt-cli
matrix:
  fast_finish: true

language: node_js
node_js:
  - 4
  - 5
  - 6
before_script:
  - npm install -g grunt-cli
matrix:
  fast_finish: true

Build on Node.js 6 also
Build on Node.js 6 also