API errors via Guzzle should not throw exception

[kingIZZZY]

When using the default cURL subsystem the response is correctly handled by the SDK Fault Handler for clients to consume as documented. But when using Guzzle subsystem by calling $dataService->setClientName('guzzle') it throws an exception by default for all HTTP 4xx and 5xx response codes, the SDK does not process it as a Fault Handler and the client cannot handle cases such as 401 Unauthorized to re-authenticate etc.

Guzzle should be configured to treat HTTP error responses same as all http responses, not throw exception.