message: chore(travis): Test only node 9,8,6
diff: sudo: false
  language: node_js
  node_js:
  - - "4"
  - - "6"
  + - "9"
  - "8"
  -before_install:
  - - curl -o- -L https://yarnpkg.com/install.sh | bash
  - - export PATH="$HOME/.yarn/bin:$PATH"
  + - "6"
  cache:
  yarn: true
  directories:
  