Assign grade based on correct answer

[jleong-openedx]

Instructors can now set a Peer Instruction question to be graded based
on participation or correct answer. Students will receive full marks
for participation-based questions upon completion. For questions based
on correct answers, no marks will be awarded for an incorrect answer.
Questions with no correct answer are participation-based only.

Step 3 now displays points earned, with colour coding.

[xcompass]

@lenglund could you take a look at the UI?

[lenglund]

1. Are the changes on staging?
2. Are these UI changes for the instructor/studio view, student view, or both?

[jleong-openedx]

1. @lenglund it looks like these changes are not on staging; @xcompass, would we be able to do this/have sandbox reflect branch 128-assign-grade-correct-answer? We would later have to switch sandbox back to branch fix-62-focus-student-engagement for when I make the appropriate modifications to Emphasize student reflection in Step 2 #137.
2. These changes are for both student/LMS and instructor/studio view (the corresponding feature issue is here).

[coveralls]

Coverage decreased (-1.06%) to 96.42% when pulling 6ad40c3 on 128-assign-grade-correct-answer into 8857b8a on master.

[coveralls]

Coverage decreased (-1.06%) to 96.42% when pulling 7e737ae on 128-assign-grade-correct-answer into 8857b8a on master.

[jleong-openedx]

@xcompass I have updated this with the package updates that fix the build-breaking issue and security vulnerability that GitHub detected.