Added testing for grading settings

Suggested Reviewers:  Studio team dev, @jzoldak 
These tests test the grading settings:
Specifically, the ability to add/delete/change grading ranges and the ability to add/delete/change grading types.

The ability to add/create/delete grading types was also checked to make sure it propagates to the subsection types.

Please note that 2 tests will not reliably work:
Deleting a grade- Was able to circumvent this with javascript
Moving the grade slider- Could not circumvent, is skipped but the framework is in place