Cosmetic fixes

app/Model/Base.php

@@ -2,6 +2,8 @@
 
 namespace Kanboard\Model;
 
+use PicoDb\Database;
+
 /**
  * Base model class
  *
@@ -20,7 +22,7 @@ abstract class Base extends \Kanboard\Core\Base
      */
     public function persist($table, array $values)
     {
-        return $this->db->transaction(function ($db) use ($table, $values) {
+        return $this->db->transaction(function (Database $db) use ($table, $values) {
 
             if (! $db->table($table)->save($values)) {
                 return false;