Git commits in Moodle 3.7.1 by David Matamoros

commit c227fc61f1789dcce7a521b67c30c8fb0220a8bf
Author: David Matamoros <davidmc@moodle.com>
Date:   Thu, 23 May 2019 23:21:27 +0800
Tag:    v3.7.1

MDL-65699 core_calendar: Check string exists for event types