Git commits in Moodle 3.6.7 by sam marshall

commit fdf8e3668f2ee971a14cd1adb93b49af7bb47161
Author: sam marshall <s.marshall@open.ac.uk>
Date:   Thu, 03 Oct 2019 21:24:11 +0800
Tag:    v3.6.7

MDL-66836 Behat: Reset unknown config variables between scenarios