add phpunit windows support

src/ZM/Store/MockAtomic.php

@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace ZM\Store;
+
+class MockAtomic
+{
+    private int $num = 0;
+
+    public function set(int $num)
+    {
+        $this->num = $num;
+    }
+
+    public function get(): int
+    {
+        return $this->num;
+    }
+}