Members of a group should be listed based on their role (bug 1315956)

The 'admin first' sort order should also sort tutors next before general members.

Change-Id: If44a85b4081b46c91a8a98a3893b828a5e29f74d
Signed-off-by: Ghada El-Zoghbi <ghada@catalyst-au.net>
Merge "Members of a group should be listed based on their role (bug 1315956)"