Git commits in Moodle 3.6.3 by Claude Vervoort

commit 703d3f1a05514b71ba4b66a17e6fd5d3aee68996
Author: Claude Vervoort <claude.vervoort@cengage.com>
Date:   Thu, 31 Jan 2019 05:13:03 +0800
Tag:    v3.6.3

MDL-64730 LTI Adv: do not ignore 0 score