Drupal 7: tpl on module

gistfile1.txt

    /**
     * Implements hook_theme().
     */
    function mymodule_theme($existing, $type, $theme, $path) {
      $theme = array();
      $theme['node__blog_post'] = array(
        'render element' => 'content',
        'base hook' => 'node',
        'template' => 'node--blog_post',
        'path' => drupal_get_path('module', 'mymodule') . '/templates',
       );
      return $theme;
    }