Schema::table('tbl_notifications_stack', function(Blueprint $table) {
            $table->foreign('notification_id', 'fk_notification_stack')->references('id')->on('tbl_notifications')->onUpdate('NO ACTION')->onDelete('CASCADE');
            $table->foreign('author_id', 'fk_notification_stack_author_id')->references('id')->on('tbl_users')->onUpdate('NO ACTION')->onDelete('CASCADE');
        });