Dependents support. fixed #190

create table:

```sql
CREATE TABLE `module_deps` (
 `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT 'primary key',
 `gmt_create` datetime NOT NULL COMMENT 'create time',
 `name` varchar(100) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL COMMENT 'module name',
 `deps` varchar(100) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL COMMENT 'which module depend on this module',
 PRIMARY KEY (`id`),
 UNIQUE KEY `name_deps` (`name`,`deps`),
 KEY `name` (`name`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='module deps';
```

restore the exists relations:

```bash
$ node bin/restore_module_deps.js
```