Release 0.1

Two user classes. Admins can generate problems, students can do the ones
assigned to them.
Users are hardcoded, problems are stored in a list.

Problems:
1. When in Admin/User screens, need to manually click "Log out" and then
exit the login form. Else login form doesn't properly exit. (Open up
task manager and terminate MathDrillGame.exe if need to)
2. Admin -  the list of users should only have students
3. Student - Infinite loop in searching for unfinished problem.
4. Student - If no problem set assigned, error. (due to it attempting to
find a problem. Just do if list length == 0, return)
5. Admin - No input validation for min/max/quantity

Note: Only admin is Bill J. Admin.