gipfl\Db\Migration - DB migration helper

Allows to apply schema migrations

Sample Directory Structure

├── src
│   └── ...
├── schema
│   ├── mysql-migrations
│   │   ├── upgrade_2.sql
│   │   ├── upgrade_3.sql
│   │   ├── upgrade_4.sql
│   │   └── upgrade_5.sql
│   ├── pgsql-migrations
│   │   ├── upgrade_2.sql
│   │   ├── upgrade_4.sql
│   │   └── upgrade_13.sql
│   ├── mysql.sql
│   └── pgsql.sql
├── README.md