fix rdlowrey/auryn#129

[koenhoeymans]

This should fix #129

I've found this issue while looking for a solution to the same problem I had in my own DI library. It seems that PHP incorrectly states that the argument accepts null. The solution I propose (I've done so in my own library) is not to collect null as an argument from reflection when no value is given by the user and reflection tells the argument is optional, rather than accepting null when reflection tells it also allows null while being optional.

[koenhoeymans]

The build fails for php versions 5.3, 5.4 and 5.5. I don't have them to test with but it seems it can be solved easily by re-using the php_version_id. The failure of HHVM probably by using the variadic function but I don't have experience with HHVM.

[Danack]

Thanks, merged in 113f8c79f30d02c70862b526f2036ed6f753292b a mere 3 years later.