Clean-up tests and use PHPStan max level for tests

tests/bootstrap.php

@@ -1,5 +1,10 @@
 <?php
-// @codingStandardsIgnoreFile
+
+/**
+ * Test bootstrap
+ *
+ * @codingStandardsIgnoreFile
+ */
 
 error_reporting(E_ALL & ~E_DEPRECATED);
 
@@ -8,30 +13,6 @@ use AspectMock\Kernel;
 require_once __DIR__ . '/../vendor/autoload.php'; // composer autoload
 require_once __DIR__ . '/phpstan-bootstrap.php';
 
-if (!function_exists('uuid_create')) {
-    // Create stub of method so AspectMock can mock this function
-    // if it doesn't exist in PHP.
-    function uuid_create()
-    {
-    }
-}
-
-if (!function_exists('uuid_parse')) {
-    // Create stub of method so AspectMock can mock this function
-    // if it doesn't exist in PHP.
-    function uuid_parse()
-    {
-    }
-}
-
-if (!defined('UUID_TYPE_TIME')) {
-    define('UUID_TYPE_TIME', 1);
-}
-
-if (!defined('UUID_TYPE_RANDOM')) {
-    define('UUID_TYPE_RANDOM', 4);
-}
-
 $kernel = Kernel::getInstance();
 $kernel->init([
     'debug' => true,