language: node_js
node_js:
  - "4"
  - "5"
  - "6"
install:
  - npm -g install yarn
  - yarn
cache:
  directories:
    - ~/.yarn
    - ~/.nvm

language: node_js
node_js:
  - 6
  - 7
  - 8
install:
  - npm -g install yarn
  - yarn
cache:
  directories:
    - ~/.yarn
    - ~/.nvm

Test against modern node versions
Test against modern node versions