Why this change?
When a site's default locale is changed, Discobot's `UserProfile#bio_raw` is not
changed and we have gotten reports about this.
What does this change do?
This change adds a `DiscourseEvent.on(:site_setting_changed)` callback
which watches for changes to the `default_locale` site setting and
updates Discobot's `UserProfile#bio_raw` when it changes.
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.
To eliminate a DDOS attack vector, we're taking the following measures:
The endpoint will be rate-limited to 3 requests every 60 seconds (per user).
A 24 hours max-age cache header is sent with the response.
The route will be hijacked to generate the certificate in the background.
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
