Enable Yarn caching on Travis (#1629)
Enable Yarn caching on Travis (#1629)

See https://docs.travis-ci.com/user/languages/javascript-with-nodejs/#Caching-with-yarn
ACPK/react-starter-kit,0xcdc/rfb-client-app,labzero/lunch,fkn/ndo,ACPK/react-starter-kit,fkn/ndo,0xcdc/rfb-client-app,0xcdc/rfb-client-app