Git commits in Moodle 3.3.6 by Guillermo Alvarez

commit 77e0eaf2a6e6cb115dfc660dceb9d2a3e636941b
Author: Guillermo Alvarez <guillermo.alvarez@blackboard.com>
Date:   Tue, 06 Mar 2018 03:28:46 +0800
Tag:    v3.3.6

MDL-61129 survey: Add colgroup attribute at survey question tables