Fix #6

```php
$data = "05001:11001:76001:13001:17001:66001:68001:63001";

$this->validator->setValues( array( 'CITYID' => 0 ));

$this->validator->name('CITYID')
                ->required('ERROR')
                ->oneOf( $data, 'ERROR' );
```
it's valid and CERO it's not one of $data