v5.1.0

New Features

• Add support for read only attributes (#298)
• Add save_all_attributes and update_all_attributes methods to support nullifying attributes. (#299)
• Add support new Event metadata feature (#300)

Enhancements and Fixes

• Fix attributes assignment for Delta (#297)
• Fix issue where files couldn't be attached to drafts (#302)
• Fix exception raise when content-type is not JSON (#303)
• Fix issue where draft version wouldn't update after update or save (#304)