language: node_js
cache:
  directories:
    - node_modules
node_js:
  - "6"
before_script:
    - 'npm install'
script:
  - npm run test

language: node_js
cache:
  directories:
    - node_modules
node_js:
  - "8"
before_script:
    - 'npm install'
script:
  - npm run test

Use node 8 on Travis.
Use node 8 on Travis.
