InheritShippingAddress does not seem to default to true

[chrischen]

Apparently on a pay call InheritShippingAddress (inherit_shipping_address) gets sent as false by default (or the docs are wrong).
https://developer.amazon.com/docs/amazon-pay-api/authorizeonbillingagreement.html
The docs state the param is true by default, and the example call in this README doesn't even mention it, so unless you somehow magically know you're by default being excluded from Seller Protection promises.

Amazon hit us with a chargeback and excluded the order from Seller Protection because this library does not document that param, nor does it adhere to the default "true" value as stated in the API docs. Even though we use the Amazon address book address, the address doesn't seem to get attached to the payment unless you explicitly pass inherit_shipping_address as true in the pay call.

This same bug was reported and fixed in the C-Sharp SDK: amzn/amazon-pay-sdk-csharp#15

So it seems sensible to have this fixed so that it is the default so it's consistent with documentation.