os:
  - linux
  - osx
language: node_js
node_js:
  - "node"
  - "9"
  - "8"
  - "6"
  - "4"
after_script:
  - npm run coveralls

os:
  - linux
  - osx
language: node_js
node_js:
  - "node"
  - "9"
  - "8"
  - "6"
after_script:
  - npm run coveralls

Remove node 4 from testing targets
Remove node 4 from testing targets