This Kata was originally created by Terry Hughes (http://twitter.com/TerryHughes). It is already on GitHub here. See also Bobby Johnson's description of the kata.
Emily Bache translated the original C# into a few other languages, (with a little help from my friends!), and slightly changed the starting position. She also wrote this article "Writing Good Tests for the Gilded Rose Kata" about how you could use this kata in a coding dojo.
More and detailed information on the original github project
This repository contains a Java-only version of the kata. This build is based on gradle and has a few more libraries (e.g. junit5, approval test and pitest) as dependencies.
Oliver