language: node_js
node_js:
  - "node"
  - "6"
  - "5"
  - "4"
  - "0.11"
  - "0.10"
before_install:
  - npm install -g grunt-cli

language: node_js
node_js:
  - "node"
  - "6"
  - "5"
  - "4"
  - "0.11"
  - "0.10"
before_install:
  - npm install -g grunt-cli
env:
  - CXX=g++-4.8
addons:
  apt:
    sources:
      - ubuntu-toolchain-r-test
    packages:
      - g++-4.8

Address Travis CI compiler version issue
Address Travis CI compiler version issue

The build for Node.js 6 failed with the following error.

Starting with io.js 3 and Node.js 4, building native extensions requires C++11-compatible compiler, which seems unavailable on this VM. Please read https://docs.travis-ci.com/user/languages/javascript-with-nodejs#Node.js-v4-(or-io.js-v3)-compiler-requirements.

These are the changes prescribed in the above link.