[Feature]: Add version flag

[jwillikers]

Describe the feature request

I'm working on packaging check_interfaces in Nix. There's an automated version check that can verify the programs version and that the program is running correctly. It would be great if check_interfaces supported a --version flag and reported the version and exited successfully. See the comment regarding this check in the PR here.

[RincewindsHat]

Hi @jwillikers,
Good point, I will take a look at it