Add IPv6 Support

[LordSimal]

I would love to be able to call this functionality

$certificate = SslCertificate::download()
    ->fromIpAddress($ipAddress)
    ->forHost($hostName);

with a valid IPv6 address as well.

But currently the ->fromIpAddress() method calls filter_var($ipAddress, FILTER_VALIDATE_IP) which only works on IPv4 addresses without any further options.

[freekmurze]

Feel free to create a PR for this. Make sure to include tests.

[LordSimal]

Do you have any recommendations for which IPv6 address (or rather which domain) I use to test the functionality?
spatie.be doesn't seem to have a IPv6 address.
Otherwise I would choose something like google.com

[freekmurze]

google.com is fine 👍