Need to determine correct ID

Need to determine correct ID if default identifier was not supported

```php
$identifier = $metadata->getName($metadata->getIdentifier(), Metadata::CAMILIZED);
$this->currentKey = $reflection->getProperty($identifier)->getValue($entity);
```

https://github.com/colibrilabs/orm/blob/master/src/Colibri/Core/ResultSet/ResultSet.php#L56