Handle tiers that creates a "prepaid" card after payment

[znarf]

Draft

User story

For "host collectives" (collectives linked to a fiscal host to manage their budget), we want to create special tiers that create a "prepaid" card after a payment is validated.

Limitations

• This should be available at first only for tiers of "host collectives". They can be recognized with their settings.hostCollective=true ie: http://opencollective.com/opensource
• The tier itself should be activated for this special behavior: settings.createPrepaidCard=true

Specification

• A prepaid card (valid on the host) will be created and owned by the account initiating the donation. Platform fees and host feeds should naturally be removed from it.
• The balance of the "host collective" should be deducted from the value once the prepaid card is created. Do we need to create a transaction to materialize that?

Data

Payment Method entry

{
    "primary" : false,
    "initialBalance" : order.totalAmount - fees,
    "CollectiveId" : order.fromCollective.id,
    "currency" : order.fromCollective.host.currency,
    "customerId" : order.fromCollective.slug,
    "service" : "opencollective",
    "type" : "prepaid",
    "data" : {
      "HostCollectiveId": order.fromCollective.host.id
    },
    "createdAt" : NOW(),
    "expiryDate" : NOW() + 1 month
}

[stale]

This issue has been automatically marked as stale because it has not had recent activity. We want to keep it in our todo list but haven't had the time to address it yet.
Thank you for your contributions!

[znarf]

It was not exactly implemented like initially specified but this is done.