Git commits in Moodle x.x.x by Robynstar

commit 474dd887d005138bf9d01f08eac5e907422e22a2
Author: Robynstar <robynstar_petirrojo@hotmail.com>
Date:   Fri, 28 Sep 2018 12:53:21 +0800
Tag:    v3.6.0-beta

MDL-44137 group: add update_groups webservice function