How do you add a "badge" in GitHub README so that it is dynamic? By "badge", I mean 
The question is even if one puts a URL in GitHub README which maps to a server returning an svg/png, how does it update automatically on GitHub README page?
As an example if you visit the link , you'd see the updated status of the issue (which is closed), but my GitHub README page still shows outdated badge, that is, shows the issue being open.
What is an example server code (say in golang) which can render github badges dynamically?
