Reverted back to Model class

lib/Models/Model.php

@@ -0,0 +1,18 @@
+<?php
+namespace MailPoet\Models;
+
+if (!defined('ABSPATH')) exit;
+
+class Model extends \Sudzy\ValidModel {
+  function __construct() {
+    $customValidators = new CustomValidator();
+    parent::__construct($customValidators->init());
+  }
+
+  function save() {
+    if ($this->created_at === null) {
+      $this->created_at = date("Y-m-d H:i:s");
+    }
+    parent::save();
+  }
+}