Gift-card syncing with Shopify / Solidus

[thisiscab]

I am unsure if the modifications required should belong in this gem or directly in the Host app, but let's write the implementation details here first.

The context is that we want customers to be able to buy gift-card on a Solidus Shop and allow that gift-card to be used on a Shopify Retail store.

The implementation we were thinking of is that:

• When we create a gift-card on Solidus we'll create one in Shopify.
  • The return value of the created Shopify will contain the gift-card code that we will use as the Solidus gift-card code
  • One problem that we'll have to solve is that in order to create a Shopify Gift-Card we need to assign it to an order or a user, so we'll have to create dummy order and make sure that we are not importing those orders to Solidus.
• If the gift-card gets used on Solidus, we nullify it on Shopify.

Please edit this message in order to add more steps / details

[thisiscab]

cc: @braidn @bryanmtl