Git commits in Moodle 3.9.0 by Tung Thai

commit 15a00bead1d7b38513c4f80adf039194cfe4ef4b
Author: Tung Thai <tungthai.it91@gmail.com>
Date:   Wed, 15 Apr 2020 18:18:32 +0800
Tag:    v3.9.0-beta

MDL-66992 core_badges: Add support to Open Badges 2.1