language: node_js
node_js:
  - "8"
  - "6"
  - "4"
before_script:
  - npm install -g mocha
script: 
  - if (( $TRAVIS_NODE_VERSION >= 6 )); then npm run test; fi
  - npm run e2e
after_success:
  - if (( $TRAVIS_NODE_VERSION >= 6 )); then npm run coveralls; fi