Git merges in Moodle 3.7.0 by AMOS bot

commit 745ab2badf4e0b0f9b9aca0fc8141b74677633bb
Author: AMOS bot <amos@moodle.org>
Date:   Wed, 10 Apr 2019 08:12:10 +0800
Tag:    v3.7.0-beta

Merge branch 'master' into install_master