Code Jam New Routes: Create User.

[D0rs4n]

Route

create_user

Goal

If the Discord user hasn't participated in a previous code jam, hence has no database entry, create a new user.
(in the new database schema, there is a field that bind jam specific details to a user, hence the route)

Response code if succeded (already exists, or created): 201
Otherwise: 400

For reference, see the Miro board. (Graph 2)