Changes to Create a line item option

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

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

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

removed the request property data/relationships/line_item/id

removed the request property data/relationships/line_item/type

removed the request property data/relationships/sku_option/id

removed the request property data/relationships/sku_option/type

added the new optional request property data/attributes/unit_amount_cents

added the new optional request property data/relationships/tags

the type request property default value line_item_options was removed

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

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