Git commits in Moodle 3.6.6 by Tom Dickman

commit b51509778bb36d72ea8806093576528cc1d492de
Author: Tom Dickman <tomdickman@catalyst-au.net>
Date:   Tue, 16 Jul 2019 07:03:54 +0800
Tag:    v3.6.6

MDL-66137 mod_assign: fixed marking workflow incorrect grade display