The package has moved to the Laravel organisation and should now be referenced as laravel/forge-sdk in your composer.json.
The starting namespace for the package has changed from ThemSaid\\ to Laravel\\.
PHP 7.2 is the new minimum version.
The upgradePHP method has been replaced by the installPHP and updatePHP methods.
The "Managing MySQL" specific functionality has been removed in favor of the new and general "Managing Databases" functionality.
The SSHKey method has been changed to sshKey.