400 error code when trying to create user via REST

Issue Description: 

When attempting to create a new user via REST API the error code returned is an http 400 error.

Resolution:

The user being created has several roles associated with it, including ROLE_SUPERUSER. Attempts to replicate in house showed one key difference in our test cases, that being in the in house test case the superuser user was used to login and then submit the request while in the customer's test case, a tenant administrator was used. Tenant administrator users typically do not have the ability to assign that role to users, as this role exists at the root level. Once they used the superuser account, creating the user, succeeded.