Enhancement: Always add path from console input

The change proposed in #262 makes the feature #251 work only with the change proposed in this PR:

## Steps to reproduce

Create a `.php_cs` file with the following contents:

```php
return Symfony\CS\Config\Config::create()
    ->fixers([
        'indentation',
        'linefeed',
        // . . . 
    ])
;
```

Create some php file `foo.php` and run

```
$ bin/php-cs-fixer fix --config-file=.php_cs --dry-run --verbose foo.php
```

## Result

```
Loaded config from ".php_cs"



[LogicException]
You must call one of in() or append() methods before iterating over a Finder.



Exception trace:
() at /Users/localheinz/foo/vendor/symfony/finder/Symfony/Component/Finder/Finder.php:688
Symfony\Component\Finder\Finder->getIterator() at /Users/localheinz/foo/vendor/fabpot/php-cs-fixer/Symfony/CS/Fixer.php:92
Symfony\CS\Fixer->fix() at /Users/localheinz/foo/vendor/fabpot/php-cs-fixer/Symfony/CS/Console/Command/FixCommand.php:284
Symfony\CS\Console\Command\FixCommand->execute() at /Users/localheinz/foo/vendor/symfony/console/Symfony/Component/Console/Command/Command.php:241
Symfony\Component\Console\Command\Command->run() at /Users/localheinz/foo/vendor/symfony/console/Symfony/Component/Console/Application.php:892
Symfony\Component\Console\Application->doRunCommand() at /Users/localheinz/foo/vendor/symfony/console/Symfony/Component/Console/Application.php:191
Symfony\Component\Console\Application->doRun() at /Users/localheinz/foo/vendor/symfony/console/Symfony/Component/Console/Application.php:121
Symfony\Component\Console\Application->run() at /Users/localheinz/foo/vendor/fabpot/php-cs-fixer/php-cs-fixer:27


fix [--config="..."] [--config-file[="..."]] [--dry-run] [--level="..."] [--fixers="..."] [--diff] [--format="..."] path
```

Updating the configuration in `.php_cs` and 

```php
$finder = Symfony\CS\Finder\DefaultFinder::create()
    ->exclude('somedir')
    ->in(__DIR__)
;

return return Symfony\CS\Config\Config::create()
    ->finder($finder)
    ->fixers([
        'indentation',
        'linefeed',
        // . . . 
    ])
;
```

doesn't help because only the file(s) represented by or in the specified path should be fixed.

## Fix

Just add the path as specified from the console already, and this works!