Changes to Create an order copy

added the new required request property data/relationships/source_order/data

request property data/type was restricted to a list of enum values

removed the request property data/relationships/source_order/id

removed the request property data/relationships/source_order/type

added the new optional request property data/attributes/apply_promotions

added the new optional request property data/attributes/ignore_invalid_coupon

added the new optional request property data/attributes/skip_errors

the type request property default value order_copies was removed

added the new order_copies enum value to the request property data/type

added the media type application/vnd.api+json for the response with the status 201