Set PHP 5.5.9 as minimum required version

[hassankhan]

PHP 5.3 is ... outdated to say the least.

Since the library is fairly mature, I think maybe we should do any last tidy ups, then do a 1.0 release with 5.5.9 set. That way, anyone still using older versions can use <1.0 and still be fine (I think)

[DavidePastore]

I think it's ok to change the minimum required version of PHP but is there a reason behind this choice?

[hassankhan]

Yep, reason being any version of PHP older than 5.5 are outdated, and users are not recommended to be running them.

[DavidePastore]

Let's do this 💃

[Potherca]

Any news on this?

[DavidePastore]

Closed by #99.