Added readinessPath to use custom path for server readiness detection

[OwlyCode]

Hello,

I have a use case where my app is behind a security firewall that redirects anonymous users to Google's oauth page. In that case Panther fails to detect that the web server is up.

Here's a proposal to add a setting that allows custom path for readiness check. For instance you could do this :

$client = static::createPantherClient([
    'readinessPath' => '/ping'
]);

$client->getCookieJar()->set(new Cookie('jwt_token', $this->getTestToken()));
$client->request('GET', '/dashboard');
// [...]

And that would check http://127.0.0.1:48008/ping instead of http://127.0.0.1:48008/

[OwlyCode]

Hello again, is there anything I can do to help integrating these changes ?

[dunglas]

LGTM

[dunglas]

Thanks @OwlyCode