refs https://github.com/TryGhost/Team/issues/1132
We have to include the Offer on the metadata for the Stripe Checkout -
as Offers with a duration of 'once' will not always be present on the
Subscription after fetching it.
Once we receive the Stripe Checkout webhook we emit an event for
subscription created - the reason we use an event is because this logic
should eventually live in a Payments/Stripe module - and we'd want to
decouple it from the Members module.
The Members module is in charge of writing Offer Redemptions - rather
than the Offers module - because Offer Redemptions are "owned" by a
Member - and merely reference and Offer. Eventually Offer Redemptions
could be replaced by Subscriptions.
refs https://github.com/TryGhost/Team/issues/1006
When disconnecting from Stripe, we currently do not remove the webhooks,
this will result in the webhooks from Stripe failing, and tending toward
a 100% error rate, which will ultimately result in emails from Stripe
about the failing webhook.
In order to stop all of that from happening, we should make sure that we
actively remove the webhook from Stripe when disconnecting.