Fix vendor location

Fixing issue with autoloader when executing from outside the source directory:
#1

Author: erkens

parallel-lint

@@ -40,6 +40,7 @@ $autoloadLocations = [
     getcwd() . '/../../autoload.php',
     __DIR__ . '/../vendor/autoload.php',
     __DIR__ . '/../../../autoload.php',
+    __DIR__ . '/../../autoload.php',
 ];
 
 $loaded = false;