* Adds second_user_id and third_user_id to Admin::Articles::Controller and Article model
- Add second_user_id to #update
- Add third_user_id to #update
- Add second_user_id to #article_params
- Add third_user_id to #article_params
- Add second and third user_ids to :limited_columns_internal_select
* Adds a second_user_id and third_user_id form field to _individual_article.html.erb
* Adds tests around adding a co-author and multiple co-authors to an article in articles_spec.rb
* First draft - all the big changes
* Changing some more references to 'internal'
* Relocate internal request tests to admin
* Relocate internal system tests to admin
* Fix trailing space
* Test fix
* Move queries from internal to admin
* Docs updates
* Rename internal stimuls controllers to admin (plus docs)
* Rename admin layout
* Fix routing after rebase
* Fixes for latest added admin interfaces
* Serviceworker ignore paths
* Start with webhooks: table and model
* Start with webhooks api
* Start with webhooks api
* Webhook::Event class and events list
* Remove commented callbacks
* Start with sending events to webhook endpoints
* A couple of tests for Articles::Creator
* Send event to webhook endpoint on article destroy
* Dispatch event on article update
* Dispatch event when an article updated from admin
* Spec for the webhook job
* One more test for the dispatch event job
* Integration-like spec for event dispatching to webhook endpoints when creating an article
* Use Addressable::URI to parse endpoint url
* Add oj as a faster fast_jsonapi backend
* Renamed serializers
* Move article serialization out of a model
* Don't allow to create a webhook event with invalid type
* Add fields for ArticleSerializer
* Fix webhook event job specs
* Specify timeout when dispatching events
* Fix webhook job spec
* Change webhook events queue name
* Change serialized article fields for the dispatchable events
* Include user data when serializing an article for webhook event
* Moved decorating out of Webhook::DispatchEvent, fixed most specs
* Fix route in ArticleSerializer
* Move Article decoration to Webhook::PayloadAdapter
* Refactor image url helpers to avoid including helpers into serializer
* Fix specs
* Default url options for production
