Removed unnecessary README
Adds #requirements to ComposedSchema with specs
Removes useless rescue
Adds indexed library_item_ids integer array column to content_items

This allows us to search through LibraryItem's content and link up which ContentItem records are associated to them.
Added Fuubar rspec formatter (fail-fast ftw!)
Added Base grape-entity with :iso_timestamp format.

Added :iso_timestamp format to all entitites' :created_at/:updated_at timestamps.

Added :iso_timestamp format to Publishing's :published_at
Refactors PUT/POST to send actual JSON in specs
Adds ComposedContentValidator and validates ContentItem's :content
Removes whitespace
Updates :content_item Fabricator
Updates seeds.rb for composed ContentItems
Updates ContentItem entity to conditionally show composed content and schema
Refactors LibraryItem specs
Adds :requirements transient attribute to ComposedSchema fabricator
Updates ComposedSchema::Rules attributes to minimum/maximum

This is done in order to follow the convention for :requirements
Refactors #composed_content and adds specs
Updates README
Fixes typo
Updates README with ContentItem.library_item_ids explanation
Updates README format for easier reading on GitHub