Complete first pass on cleanup of models.py

- mostly involving the abstraction of validators int seperate file

Closes #176
1 job for 176-business-logic in 1 minute and 31 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
failed #5391
Go-py3.6

00:01:31

 
Name Stage Failure
failed
Go-py3.6 Test
?            -
+ <RegisteredUser: dhaynes - Approval Status: False>


----------------------------------------------------------------------
Ran 76 tests in 31.509s

FAILED (failures=2)
ERROR: Job failed: exit code 1