clarify loggingMiddleware is not yet defined
clarify loggingMiddleware is not yet defined

While following the tutorial (and thanks a lot for it), on the Transport Logging section, I got an error that loggingMiddleware is not defined, up to that point I had followed the code snippets and run/test, took me a while to understand the code wasn't ready to be ran. There's an open issue #17 which also pointed this out but the pull request doesn't address this part. Thank you for your awesome work!
go-kit/go-kit.github.io