Refactor - Authority roles should be maintained in an Enum
Description
We currently have the following roles:
ROLE_ADMIN, ROLE_TEACHER, ROLE_TA, ROLE_STUDENT
Since we have a fixed set of values, we should replace these strings with an enum.
Priority - Medium
This would make the could more maintainable and would reduce the chance that typing errors are introduced
Definition of done
When roles have been replaced with enums.