Add support for IP Address Ranges

[Vadoola]

I had been thinking on trying to add this feature myself (and maybe I'll still try and get around to it), but I've been busy. So I thought I would open an issue in case someone else can get around to adding it before I do.

Add support for pinging a range of IP Addresses, similar to how it works in nmap.

something like gping 192.168.1.10-15 instead of having to type out gping 192.168.1.10 192.168.1.11 192.168.1.12 192.168.1.13 192.168.1.14 192.168.1.15

[Vadoola]

This is someone similar to https://github.com/orf/gping/issues/274, but it's not exactly the same. I imagine there would be overlap in the implementation and they could possibly implemented together.

[ndit-dev]

as well as range specified as IP/CIDR, such as 192.168.1.16/28