message: chore(ci): make Travis CI build fast!
diff: @@ -5,6 +5,7 @@ node_js:
  - "6"
  - "8"
  - "10"
  -cache:
  - directories:
  - - "node_modules"
  +# running tests only when pushing a commit in master except PRs
  +branches:
  + only:
  + - master
  