[3.6] bpo-30917: IDLE: Add config.IdleConf unittests (GH-2691) by terryjreedy · Pull Request #2753 · python/cpython

I clicked .diff at the bottom of #2754, saved to my disk, applied, confirmed change, confirmed idle tests still run on win10, committed, and pushed. I expect CI to pass again, the real test will be the Win7 buildbot, which failed the 3.7 merge, as reported in bpo 30968.