Merge pull request #96 from Gummibeer/patch-1

add relation property mapping

Author: johguentner

src/Entities/Properties/Property.php

@@ -177,6 +177,7 @@ private static function mapTypeToClass(string $type): string
             case 'files':
             case 'formula':
             case 'rollup':
+            case 'relation':
                 $class = str_replace('_', '', ucwords($type, '_'));
 
                 return 'FiveamCode\\LaravelNotionApi\\Entities\\Properties\\'.$class;