Add gds-sso configuration
Add section_note and chapter_note endpoints to the API
Spec SectionNote controller's #show action
Add SectionNote create spec
SectionNote update spec
Add SectionNote deletion spec
Fix Api Sections controller specs
Add ChapterNote controller
Convert ChapterNote#chapter_ids to string

Add spec for Chapters#index
Fix section and chapter note loading

find_or_create does not work well with validations and creation invokes
them
Cleanup, remove unnecessary files