[WIP] Move to gorm

## Warrning
1. Test fails because this is ORM problem ( i think tomorrow this will be fixed ) https://github.com/jinzhu/gorm/issues/202
2. This PR change table column names, and some SQL Queries

## Features
1. Support PostgreSQL, SQLite, MySQL
2. Migrations via ORM
3. Some SQL Queries now use JOIN
4. Use DATABASE_URL instead driver/source flags (*tcp* only for PostgreSQL and MySQL)
```sh
DATABASE_URL="sqlite:///home/bugagazavr/drone.sqlite" make run
DATABASE_URL="postgres://postgres://postgres@127.0.0.1:5432/drone?sslmode=disable" make run
DATABASE_URL="mysql://root@127.0.0.1:3306/drone" make run
```
5. Test data renamed to fixtures and use ORM too