Users
first_name - string
last_name - string
email - email
username - string
password - string
exercises_running - integer

Classes
name - string
description  - string
students - ManyToMany(Users) 
instructor - ManyToMany(Users) 
exercises - ManyToMany(Exercises) 
attempted - ManyToMany(Submissions)

Exercises
name - string
description - string
answer - string

Submissions
student - ForeignKey(Users)
exercises - ForeignKey(Exercises)
classes - ForeignKey(Classes)
submitted_answer - String

Settings
name - String
ram - Integer
cores - Integer
instances - Integer