Enable the content_moderation module. Use the following drush config-import command to import the configuration into your Drupal 8.6.0-dev site.

drush config-import --partial --source=/PATH_TO_REPO/content_moderation_configuration

Users are content in Drupal. After enabling the content moderation module and importing the configuration, create three users with roles assigned like this:

1. Author user with Author role
2. Reviewer user with Reviewer role
3. Publisher user with Publisher role