Update API (and specifically Zapier) to handle allocating users to Tiers

The current API (and Zapier integration) allows for external applications to create a user with a free membership level, or a complimentary premium membership.

It would be good, now that tiers have been added, to enable external applications to create members and add them to, or remove them from, specific tiers.

For example, because of the need to charge VAT, we now have our payments handled by Zoho Subscriptions (but stick with Ghost for all publishing because we love it for writing, publishing to the web, and emailing). Zoho then uses Zapier to add the user, and a complimentary premium subscription in Ghost. (It’s also handy because Zoho can also set up their Teachable access etc at the same time)

In an ideal world, Zoho (or any other billing tool) would be able to use Zapier, or the API, to add them to a specific tier.

Thanks for a great tool with Ghost