Version 4.0.0

Improved

• Use Ruby 3.0.
• Upgraded baseimage-docker to rel-2.1.0.
• It is now possible to define the user name as well as UID and GID of the
  main user running the container. By default, this will be user dora with
  UID 1000 and GID 1000.
• It is now possible to bootstrap a new Rails application, plugin or whatever
  because the script that bootstraps the container no longer errors out if there
  is no Rails application present. Instead, when configured not to pull any Git
  repository (GIT_PULL=false), the script will gracefully exit if there is
  no Rails application.
• The WEBHOOK_SECRET environment variable was renamed to
  DORA_WEB_UPGRADER_SECRET to play nice with DoraWebUpgrader.

Changed

• The default name for the Git branch to checkout was changed from master to
  main. On the other hand, e-mail addresses such as webmaster@... were not
  changed. However, in the author's opinion, where is a difference between
  "master" and "slave" terminology on the one hand and "master" as in
  "someone is professionally trained to do something really well" on the other
  (in Germany, "Meister" is a professional title).
• The msmtp configuration now uses TLS, rather than STARTSSL, to communicate
  with the SMTP server.

Fixed

• Adjust runit's service permissions for sidekiq so that it can be stopped and
  restarted by the 'dora' group.
• The shared-mime-info package is now explicitly installed (following recent
  licensing changes in the wider Rails ecosystem).
• Prevent flooding the container output with warnings if there is no log
  directory.
• When upgrading the application, upgrade-app.sh will now stop and re-start
  the sidekiq service.
• Properly add the restart-app.sh script rather than another copy of the
  upgrade-app.sh script into the image.