Submission part names incorrect

[brandonmpark]

The part names on the submission are offset by 1, with the last part being moved to the top and the rest being shifted down. The scores and feedback are still in the right order.

[tengznaim]

I think I'm facing similar issues in Exercise 5

[PaulFenton]

I think this was a miss when upgrading to the new grading system. This PR fixes it.