message: Fix travis node version
diff: language: node_js
  -node_js:
  - - "6"
  - - "8"
  - - "10"
  +
  install: npm install
  jobs:
  @@ -12,6 +9,10 @@ jobs:
  script: npm run lint
  - stage: tests
  script: npm run test
  + node_js:
  + - "6"
  + - "8"
  + - "10"
  - stage: coverage
  script: npm run ci-test
  node_js: "10"
  