Subcommand 'milestone list'

[RichardHitier]

It would then be easyer to know what ID to pass to -M option

[leandro-lucarella-sociomantic]

Hi @RichardHitier, thanks for your suggestions. Sadly I don't have plenty of time to spend on these, but they are most pretty easy to implement. If you know a bit of Python you could give it a shot (and feel free to ask for pointers on getting started!). PRs definitely welcome :)