Remove omitempty tag from AmountAllocations's amount field

[borosr]

Problem:

I got the following error when I tried to send a Credit Card verification request with a 0 amount.

{
    "request_id": "some_id",
    "error_type": "request_invalid",
    "error_codes": [
        "sub_entity_amount_required"
    ]
}

That happened because the amount_allocations's amount field was 0, so the json.Marshal(...) removed it from the result JSON object.

Solution:

I recommend removing the omitempty tag from this field because the amount should always be present.