It's very easy to forget to add `require 'rails_helper'` at the top of every core/plugin spec file, and omissions can cause some very confusing/sporadic errors.
By setting this flag in `.rspec`, we can remove the need for `require 'rails_helper'` entirely.
This handles a few edge cases which are extremely rare (due to the UI layout), but still technically possible:
- Ensure users are authenticated before attempting association.
- Add a message and logic for when a user already has an association for a given auth provider.