Update V018 and V021 level from MINOR to PATCH.

V018/V021: A final class cannot be inherited, thus any protected code is not visible to clients.

Author: tomzx

src/PHPSemVerChecker/Configuration/LevelMapping.php

@@ -24,10 +24,10 @@ class LevelMapping
 		'V015' => Level::MAJOR,
 		'V016' => Level::MAJOR,
 		'V017' => Level::MINOR,
-		'V018' => Level::MINOR,
+		'V018' => Level::PATCH,
 		'V019' => Level::MAJOR,
 		'V020' => Level::MAJOR,
-		'V021' => Level::MINOR,
+		'V021' => Level::PATCH,
 		'V022' => Level::PATCH,
 		'V023' => Level::PATCH,
 		'V024' => Level::PATCH,