Remove grading of exercises

[leesjensen]

We could mark all of the small assignments as exercises and then include them as prerequisites for the 8 major deliverables with a note such as:

This has the benefit of reducing TA grading load since they don't really look at them anyway. It also removes the toil of students having to submit simple things to Canvas over and over.

The danger is that they don't do the preparatory steps to be successful with the deliverables.