Do not pull AKAs from Github OAuth #63
Description
AKAs should only ever be provided if there is a clash between two usernames. I should update the schema to:
- Disallow unique site+username combos (only make the username part unique, it'd be easy to "hijack" someone's account by making it on a different site)
- Do not pull the AKA from github oauth
- If there is a username clash, ask for the aka similarly to how we ask for the user email