Fix addScopes method pushing the array of scopes

Author: mariovalney

src/Services/DataTable.php

@@ -550,7 +550,7 @@ public function addScope(DataTableScope $scope)
      */
     public function addScopes(array $scopes)
     {
-        array_merge($this->scopes, $scopes);
+        $this->scopes = array_merge($this->scopes, $scopes);
 
         return $this;
     }