Git commits in Moodle 3.6.x 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

commit 8d84ee97dafc8ff78cf8487fc8a0e17772022bff
Author: Claude Vervoort <claude.vervoort@cengage.com>
Date:   Mon, 10 Dec 2018 23:26:12 +0800
Tag:    v3.6.2

MDL-64357 ltiservice_gradebookservices: fix cleanup deleting lineitems

commit 29acede1f08150ddf3953faa13b9e82701f84c1e
Author: Claude Vervoort <claude.vervoort@cengage.com>
Date:   Thu, 26 Jul 2018 23:20:04 +0800
Tag:    v3.6.0-beta

MDL-62993 ltiservice_memberships: make message an array per spec