Fix "Access to undefined property" rule violations

lib/Models/Model.php

@@ -77,6 +77,7 @@ if(!defined('ABSPATH')) exit;
 class Model extends \Sudzy\ValidModel {
   const DUPLICATE_RECORD = 23000;
 
+  public static $_table;
   protected $_errors;
   protected $_new_record;
 
@@ -311,4 +312,4 @@ class Model extends \Sudzy\ValidModel {
     $this->setError($this->getValidationErrors());
     return $success;
   }
-}
+}