Some big coursier features

[poslegm]

Hello!

I am trying to use this library to replace big coursier and faced several problems:

1. How can I provide FileCache with ttl into Fetch instance?
2. How to create RefreshLogger?
3. How to create sonatype repository?

I need them to migrate this to java interface without full coursier dependency.

If there's no purpose to keep coursier-interface as small as possible I am able to contribute the features I need.