Add an arbitrary map of ID's (foreign keys) on Customer

[adamdecaf]

We need to allow and store an arbitrary map of ID's (salesforceId, etc) to centralize lookups and foreign key relationships. This helps integrate external services with this project by offering one location to store all relationships with a customer.

Notes: #9

[wadearnold]

The map of ID's would allow the Customer to know which products are associated with the CustomerID

{"salesforceID": "00530000000ibYc", "paygateID": "00530000000ibYc"}

I still have a question on mapping to accounts in GL. A Customer can have several accounts. Do we want to allow for duplicate name keys in the map?

[{"accountID": "cdd71036-3fff-4a22-b364-20bd0c284cb3"}, {"accountID": "cdd71036-3fff-4a22-b364-20bd0c284cb3"}]

Here we can have multiple of the same Key. Maybe Accounts is such a common use case with severalaccountID that we make it's own property?

[adamdecaf]

I wasn't going to store GL account IDs in this map. Instead I was going to keep GL having routes like /customers/:id/accounts.

[wadearnold]

Got it. As always I like your ideas better.

[adamdecaf]

Oh, if callers want to store multiple ID's they can do so in their own format. I assume most systems would use , but some use | or other delimiters.