What you can do is kind of half measure:

Config::set('database.connections.foo', [
    'driver' => 'mysql',
    'host' => 'localhost',
    'port' => '3306',
    'database' => 'foo_db',
    'username' => 'root',
    'password' => 'secret',
    'charset' => 'utf8',
    'collation' => 'utf8_unicode_ci',
    'prefix' => '',
    'strict' => false,
    'engine' => null,
]);

$result = DB::connection('foo')->select('show tables'));

Hi, if u want add custom driver with database for it, jst add your custom dirver to config/database.php and create console artisan command on run which u will modify db settings or .env file, for example:

php artisan db:select --database=databasedriver --databasename=my_custom_database

For more info. read Artisan Laravel docs.