(WIP) Class diagram transfer

A start at transferring content from the class diagram into code.  Focuses on School/Course/Klass/Educator/Student type models.  

@Dantemss I'd appreciate a once over of this PR if you have a chance.
If you used a join table, this would be has_many :klass_educators (or similar)
then has_many :educators, through: :klass_educators