language: node_js
addons:
  firefox: latest
node_js:
  - "8"
before_install:
  - export DISPLAY=:99.0
  - sh -e /etc/init.d/xvfb start
  - sleep 3
script:
  - npm run test
env:
  global:
    - FIREFOX_BINARY: firefox

matrix:
  include:
    - script: npm run test
      env:
        global:
          - FIREFOX_BINARY: firefox
      before_install:
         - export DISPLAY=:99.0
         - sh -e /etc/init.d/xvfb start
         - sleep 3
    - script: npm run build
      env: BUILD_NOTES
    - script: npm run lint
      env: LINT
      before_script: npm run build
      before_install:

language: node_js
addons:
  firefox: latest
node_js:
  - "8"
before_install:
  - export DISPLAY=:99.0
  - sh -e /etc/init.d/xvfb start
  - sleep 3
  - npm i -g npm@6
script:
  - npm run test
env:
  global:
    - FIREFOX_BINARY: firefox

matrix:
  include:
    - script: npm run test
      env:
        global:
          - FIREFOX_BINARY: firefox
      before_install:
         - export DISPLAY=:99.0
         - sh -e /etc/init.d/xvfb start
         - sleep 3
    - script: npm run build
      env: BUILD_NOTES
    - script: npm run lint
      env: LINT
      before_script: npm run build
      before_install:

Use npm 6 to install things
Use npm 6 to install things