/**
  * Run the upgrade routine if necessary.
  */
 public static function upgrade()
 {
     $current_version = get_option('itelic_version', 0.1);
     if ($current_version != self::VERSION) {
         /**
          * Runs when the version upgrades.
          *
          * @param $current_version
          * @param $new_version
          */
         do_action('itelic_upgrade', self::VERSION, $current_version);
         update_option('itelic_version', self::VERSION);
     }
     foreach (get_tables() as $table) {
         if (!Manager::is_table_installed($table)) {
             add_action('all_admin_notices', function () {
                 echo '<div class="notice notice-error"><p>';
                 _e("We weren't able to install the tables necessary for Licensing to work. Please contact support.", Plugin::SLUG);
                 echo '</p></div>';
             });
             if (!function_exists('\\deactivate_plugins')) {
                 require_once ABSPATH . 'wp-admin/includes/plugin.php';
             }
             \deactivate_plugins(__FILE__);
             break;
         }
     }
 }