No try/except for if a username has been used before. Currently it just errors.

[MaxwellCoriell]

Issue description

When registering a new user, if a username is already taken, it errors out on submit.

Steps to reproduce the issue

1. Load application
2. Make migrations
3. Create a user (REMEMBER THE EXACT USERNAME)
4. Log out of that user.
5. Register a new user, and try to create one with the same, exact username.

What's the expected result?

• There should be a try/catch here, instead of an error.

What's the actual result?

• It catches that a username is already in use, but it freaks the fuck out when you hit submit.