More helpful error response

[mattattui]

Currently when the policy is violated, only a simple "Not allowed." response is sent. I'd appreciate it if the message was a little more specific, for instance "Access denied by CORS policy". Alternatively, the ability set a custom message or even supply a custom response would be great!

[asm89]

👍 if you want to make this configurable

stack-cors/src/Asm89/Stack/Cors.php

Lines 55 to 57 in 1c80315

	if (!$this->cors->isActualRequestAllowed($request)) {
	return new Response('Not allowed.', 403);
	}

[davidbarratt]

I would instead remove the error responses completely. See #65

[barryvdh]

We've removed the errors.