feat(soap): adds support for returning SOAP faults

[outofcoffee]

fixes #618

Returning fault messages

If your WSDL document defines a fault, then Imposter can generate a sample response from its type.

To return a fault you can:

1. set the response status code to 500, or
2. set the response.soapFault configuration property to true, or
3. use the respond().withSoapFault() script function

Example configuration to respond with a fault

plugin: soap
wsdlFile: service.wsdl

resources:
  - binding: SoapBinding
    operation: getPetById
    response:
      statusCode: 500

Tip
Use conditional matching with resources, to only return a fault in particular circumstances.

Scripted example

Setting the status code to 500 will trigger a fault message to be returned if one is defined within the WSDL document.

respond().withStatusCode(500)

or:

respond().withSoapFault()