Added description and autoload section in composer.json

1) Исправляем ошибку валидации файла composer.json
```bash
php-antispam$ composer validate
./composer.json is valid for simple usage with composer but has
strict errors that make it unable to be published as a package:
See http://getcomposer.org/doc/04-schema.md for details on the schema
description : is missing and it is required
```

2) Добавляем классы в автолодинг композера. 

3) Добавляем gitignore