ZIftrShop now natively supports variants on products.

In addition to admin area changes to support this new feature, the following changes have been made to the API:

• New "variants" array on products.
• Order items now contain "variant_id"
• Customizations on product now contain "is_variant"
• Assets on products now contain a "variant_ids" array
• Price tables on products now contain a "variant_ids" array
• The field "sku" is now injected into order items
• Additional validation is now in place to validates customizations and variants to help prevent invalid data from being saved.