message: better yarn-compatible caching
  the node_modules directory is listed so we don't have to rebuild native deps each time
diff: @@ -30,10 +30,10 @@ env:
  - JAVA_HOME=/usr/lib/jvm/java-8-oracle
  cache:
  + yarn: true
  directories:
  - - $HOME/.npm
  - - $HOME/.cache # includes bowers cache
  - - $HOME/.yarn-cache
  + - node_modules
  +
  before_install:
  - npm config set spin false
  