CLONE - A teacher can change the order in which assignment submissions are listed

This test requires an assignment with several submissions.

1. Login as a teacher, access the assignment and follow the 'View/grade all submissions' link.
2. Try sorting the submissions by first name by clicking the 'First name' heading.
3. Click the 'First name' heading again and check that the submissions are now sorted in the reverse order.
4. Try hiding one of the columns by clicking the hide icon next to a particular column heading.