Open to adding an `expanded` method on IP?

[emil-nasso]

Hi!

I (we) find the library very useful. I am missing one feature though, for it to completely fulfill my "IP needs".

Would you be open to accepting a pull request adding a expanded(): string method to the IP class?

It would work in the following way:

IP::parse('::1')->expanded(); // would return: 0000:0000:0000:0000:0000:0000:0000:0001
IP::parse('127.0.0.1')->expanded(); // would return: 127.0.0.1

I would include test (of course).

I wanted to check in first, because it seems like the library hasn't been updated in a long time.

The IP standards doesn't really see frequent changes either so maybe the library is regarded as "feature complete"? :)