v4 - Inauguration

composer require eustasy/authenticatron

IMPROVEMENT: Launch Composer package: https://packagist.org/packages/eustasy/authenticatron
MAINTENANCE: Drop PHPQRCode for jysperu/PHP-QR-Code
MAINTENANCE: Add PHP Unit tests with PHPUnit
DEPRECATED: Remove deprecated mcrypt library
NOTE: Updated eustasy/.Normal to 3.0
NOTE: Removed Codacy, Travis-CI
NOTE: Regular testing against PHP 8.3, 8.2, 8.1, 8.0