Specify exact ruby-version
Add icalendar gem
Move Sequel initialization to a separate initializer
Add ActiveModel compatibility
Set correct jsonapi content-type
Sequel: remove explicit require
Bundle update
Rewrite represent helper
Outline basic formatters
Prepare additional representers
Setup resource representer
Fix representers and booting
EventRepresenter: define collection wrapping
Add and setup forked json_spec
Use DatabaseCleaner
Fix event_resource integration spec