Instructor_MapGradersToGroupings

Story Description

When the deadline for a submission has passed, the instructor can assign submissions to specific Graders so that they can start marking the submissions. It should be possible to "reuse" certain mapping between Graders and submissions, in order to reduce the work required by the instructor.

Tests

• Test if "reuse" of submission-Grader mappings work as expected
• Check that each submission is assigned to one Grader only

(no double-mappings) * Test if mappings show up appropriately for Grader users