Test RedirectResponse problem report

[jim-parry]

Added tests for response->redirect() and redirect(), and both seem ok.
Closes #1393

[jim-parry]

@natanfelles Made an adjustment to Common::redirect() that looks like it has fixed the problem.

[natanfelles]

Not solved. But I see a light:

CodeIgniter4/system/HTTP/Response.php

Line 759 in fb60b92

$this->sendHeaders();

Headers are sent before the fluent method ->setCookie() is called

[natanfelles]

And is called again in send():

CodeIgniter4/system/HTTP/Response.php

Lines 633 to 651 in fb60b92

	public function send()
	{
	// If we're enforcing a Content Security Policy,
	// we need to give it a chance to build out it's headers.
	if ($this->CSPEnabled === true)
	{
	$this->CSP->finalize($this);
	}
	else
	{
	$this->body = str_replace(['{csp-style-nonce}', '{csp-script-nonce}'], '', $this->body);
	}
	$this->sendHeaders();
	$this->sendBody();
	$this->sendCookies();
	return $this;
	}

Maybe because of this works with the Response but not with RedirectResponse.

Firefox Raw Headers repeat some headers: #1393 (comment) - because of the headers sent in redirect() and send(), again.

Something tells me this is there in bootstrap.php

[jim-parry]

sendHeader() in redirect() looks out of place, I agree.
I eliminated it, and that does not affect the unit tests - they still pass.
This could very well be something not-testable with unit testing ... headers are a pain at the best of times with phpunit.
In any case, I pushed the change.

[jim-parry]

The travis-ci failure is from Redis tests, not related. This is good to test.