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 plugin is only useful for developers, however, making it core allows us to centralize any component modification in one commit.
This integration also adds a new site_setting: `styleguide_admin_only` which allows to enable a styleguide on a live site while restricting visibility to admins only.
By default, styleguide is disabled.
Loïc Guitaut
Phil Pirozhkov
David Taylor
Joffrey JAFFEUX