With this update, the domain structure for Drupal projects has changed a little bit, because wildcard ssl certificates only support a sub-domain, but not a sub-sub-domain. So we now have the structure like this:
traefik.docker.localhost
PROJECT.docker.localhost
pma-PROJECT.docker.localhost
mailhog-PROJECT.docker.localhost
etc
You can now call ahoy traefik rewrite to completely rewrite your Traefik config from scratch, i.e. this is useful for the migration from Traefik 1 to Traefik 2.