language: node_js
cache: yarn
node_js:
  - 7
  - 8
  - stable
install:
  - yarn
script:
  - yarn ci

language: node_js
cache: yarn
node_js:
  - 7
  - 8
  - 9
  - stable
install:
  - yarn
script:
  - yarn ci

Add Node 9 to CI config.
Add Node 9 to CI config.
