don't list courses multiple times on the user grades page if that user has
multiple enrollments in a course.
test-plan:
- as a student with multiple enrollments in a course and enrollments in
> 1 courses
- visit /grades, make sure courses are listed once.
Change-Id: Icd3722ba07070fc6453e7395a833c701c447860f
Reviewed-on: https://gerrit.instructure.com/9247
Tested-by: Hudson <hudson@instructure.com>
Reviewed-by: Brian Palmer <brianp@instructure.com>
Simon Williams