So I've been looking into this and I updated get-all-atps-for-rtp.spec.js with a new response test.

I pushed the following 'bad' data through as the response:

```
{
    data: [
        {
            atpID: '5aeadbff0139b01a9ac983ea',
            rtpID: '5aeadbff0139b01a9ac983e7',
            payerID: '79a26d981246978135edadf1',
            amount: {
                value: 101,
                currency: 'GBP'
            },
            lastUpdate: '2018-05-03T09:53:03.746Z',
            status: 'Failed',
            payerDetails: {
                payer: {
                    email: 'servertest1@comcarde.com',
                    firstName: 'Server',
                    lastName: 'Test'
                },
                card: {
                    cardPAN: '4*** **** **** *111',
                    nameOnAccount: 'Server Test'
                }
            },
            payeeID: 'dc870f553840a414962875b3',
            payeeInstrument: {
                accountType: 'Worldpay Online Payments Account'
            },
            transactionDetails: {
                orderDescription: 'create RTP for the user 79a26d981246978135edadf1 for List Test'
            },
            resultDetails: {
                errorDetails: {
                    statusCode: 400,
                    code: 538,
                    info: 'Error processing payment',
                    processorResponse: {
                        customCode: 'BAD_REQUEST',
                        message: 'Expiry date [1/2000] is in past'
                    }
                }
            },
            lastVersion: 4
        }
    ]
}
```

Swagger was happy to accept this and didn't give me an error.