* Update conversation's updated_at when a message is created/saved
* changed teh ordering of conversation to be based on `updated_at` rather than `created_at`
* add sidekiq web view if the user is an administrator
* add sidekiq setup configuration and support
* update devise to use delivery_later method and update test
* update conversation to use deliver_later instead of deliver
* Update Routes
* Add Procfile for Heroku One-Click Start
* updating docs
* update concurrency and Procfile for supporting Heroku Free Dyno
* update Procfile.dev
* Add annotate gem to the project
* Annotate models, fixtures, factories and model_specs
* Keep annotations only in Models
* Remove unwanted changes in model specs
* Exclude auto_annotate_models from rubocop
* Add Conversation factory with dependent factories
* Include FactoryBot methods in rspec config
* Add unit tests for public methods of Conversation model
* Move Current model into a separate file in lib folder
* Disable Metrics/BlockLength rule for db/migrate and spec folders
* Get rid of global $dispatcher variable
* Create Message#unread_since scope
* Refactor callback methods in Conversation model
* Create Conversations::EventDataPresenter
* Add translation keys for activity messages
* Add pry-rails gem
* Refactor Conversation#notify_status_change
* Add mock_redis for test env
