Implement logr LogSink interface

[secustor]

We are using modules from different projects where each is using a separate logging library.
To solve this we are using Logr which provides an interface which has been already implemented in many different go logging solutions.

I have seen #5, but does this apply here too?

This would definitely ease the adoption of go-kit.

[ChrisHines]

I think the answer is yes. go-kit/log defines a simple interface that anyone can use or implement without need to add code to this repo. It looks like many of the Logr adapters are hosted in the same Github org as the core package. I recommend doing the same for a go-kit/log adapter for Logr if it is needed. I don't think that the go-kit project wants to maintain it.

[tonglil]

Hello @secustor, I've written an adapter for logr recently: https://github.com/tonglil/gokitlogr

[secustor]

Thanks! I will definitely take look!