Requires incorrect

[joseph-bing-han]

\BenSampo\Enum\Enum::getLocalizedDescription(value): ?string
requires PHP 7.1 but you write require PHP 7.0, so I got the error message:

In Enum.php line 100:
Parse error: syntax error, unexpected '?'

[BenSampo]

Hi @joseph-bing-han and @me-shaon - firstly thanks both for pointing this out and for supplying the fix. I'm more than happy to merge your changes, @me-shaon, to make this package compatible with PHP 7.0 although I'd like to ensure that it does indeed work and that I don't break compatibility again in future by adding some automated testing in travis.

I currently have travis set up, but it's only testing with one environment configuration. You can see from my recent commit history (that I've since reverted) that I tried to configure travis to test in multiple environments. Unfortunately I could never get it to work for PHP 7.0. It was actually failing before ever testing the package, something to do with version mismatches when it was trying to do composer install. If either of you have any travis experience, it would be great if you could take a look - I'm pretty busy at the moment, so I probably wont get a change to take a look again myself for a while.

Cheers!