CLONE - A teacher can choose whether to allow late assignment submissions

This test requires an assignment with file submissions enabled.

1. Login as a teacher, update the assignment and set a due date in the past. Do not set a cut-off date.
2. Login as a student and upload a file.
3. Check that the file is uploaded successfully and a download link is displayed together with the submission date and time in red (indicating that it is late).
4. Login as a teacher and access the assignment.
5. Follow the 'View all submissions' link and click the Grade link for the late submission
6. Check that the submission displays the due date and a message saying how late it was submitted.