changes @ deploy command. added rollback exception functionality.

Related to [#142](https://github.com/andres-montanez/Magallanes/issues/142)

Added RollbackException class.
Added RollbackException catch @ deploy command.

How to:
```php
namespace Task;

use Mage\Task\RollbackException;
use Mage\Task\AbstractTask;

class TestTask extends AbstractTask
{
    public function getName()
    {
        return 'Run test task';
    }

    public function run()
    {
        $result = false ; /* do something here*/
        if(!$result) {
            throw new RollbackException('Codeception test - failed');
        }
    }
}
```