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.
Email change requests are never deleted no matter if they completed
successfully or not. The abandoned requests have the disadvantage of
showing up as unconfirmed emails in user's preferences page.