Add GitHub actions CI similar to AppVeyor

[arturcic]

[asbjornu]

Resolved by #1966.

[asbjornu]

Hm, I just realized this issue may be about setting up GitHub Actions for the GitVersion repository on GitHub, and not about GitVersion itself supporting GitHub Actions... 🤔

[asbjornu]

Looks like #1975 is taking a jab at this?

[stale]

This issue has been automatically marked as stale because it has not had recent activity. After 30 days from now, it will be closed if no further activity occurs. Thank you for your contributions.

[arturcic]

This one was implemented