UTF-8 encoding issue

[dragspas]

If you paste name like this 'Ren\xE9e Osborne', parse() will accept this input, but it will trigger an Error:
Error: Return value of TheIconic\NameParser\Part\AbstractPart::camelcase() must be of the type string, null returned

To prevent this I'm using ...->parse(utf8_encode($nameString));, but you should probably cover this issue in your repo.