Merge branch 'master' into rocket-mailer

* master: (24 commits)
  Add default allowed file upload
  Fix #1381
  add SECURITY.md
  Using official emojione package
  Using official emojione package
  3,000 commits!!
  Created and pushed by LingoHub. Project: 'Rocket.Chat' by User: 'gabriel.engel@gmail.com'.
  try new guest count every loop
  sorting i18n strings
  Created and pushed by LingoHub. Project: 'Rocket.Chat' by User: 'gabriel.engel@gmail.com'.
  use correct settings for livechat app
  Created and pushed by LingoHub. Project: 'Rocket.Chat' by User: 'gabriel.engel@gmail.com'.
  meteor update
  update old build script
  there is no message to update yet
  livechat room publish
  room icons
  added back _colors files
  livechat route
  fixing livechat route
  ...