Updated Drupal to 8.6. This goes with the following updates because it's possible...

[yaffs-website] / web / core / profiles / testing_install_profile_dependencies / testing_install_profile_dependencies.info.yml

name: 'Testing install profile dependencies'
type: profile
description: 'Profile for testing that install profiles can require a module.'
version: VERSION
core: 8.x
hidden: true
dependencies:
  - dblog
install:
  - ban
themes:
  - classy