Micropay endpoint

[agravitis]

Class constructor signature should be TwinClient({url: "https://blah.blah.biz.todaq.net/", apiKey: "xyz"}).

Create an info() method that calls that endpoint without auth.

The method should be micropay(url, tokenTypeHash, amount) . The method should:

• spin up another TwinClient for the provided url and call info() on it.
• get the destinationAddress from there; also verify that tokenTypeHash and amountmakes sense, otherwise error intelligently using a custom error of type TwinMicropayError , subclassed from TwinError. The custom errors can be subclassed further into TwinMicropayAmountMismatchError and TwinMicropayTokenMismatchError.
• Then attempt to perform the payment and proxying. Stream results back to the user. Convert any errors we don't know about into TwinErrors.

[sfertman]

The method should be micropay(url, tokenTypeHash, amount) . ...

Enterprise server can accept any http method + body if required by the paywall server. micropay(url, tokenTypeHash, amount) signature doesn't allow for anything but a request with a predetermined method (GET?) and no body.

Alternatively we could add optional request config like micropay(url, tokenTypeHash, amount, { method?, body?})