This is awesome! I have searched high and low for an easy way to do this. Applescripts, Alfred workflows, clipboard tricks, macros, entire applications, dashboard tools, Apple services, workflows, ... I think I made my point.
I just wanted something easy.
This is it. You have, literally, solved a multi-year search for a simple way to convert text to different cases.
Also.. I'm not a coder, programmer or anything else so even if I found that github installation, I'd fail to make it work.