Yubikey 5C case with pivot

A slightly remixed version of the keychain case for the Yubikey 5C. The original versions had a hole that was too small for my keyring. When I made the hole larger, it just barely fit, but the case was really stiff on my keychain and made the whole thing awkward in my pocket.

I modified it slightly so that I could use a 9mm D-ring and a small pivot. These make the case more flexible if you keep it in your pocket.