Closing in on Yirgacheffe 2.0

I filed the first issue about making a 2.0 release Yirgacheffe in the middle of last year, and now I finally have a PR for it after a couple of days with the code hatchet. As it stands, whilst the code churn seems high with 65 files touched and +1,823 -2,744 line changes, it's actually a relatively minor change, as most of that is tidying up from me removing code, and some renaming things. You can see we've lost close to 1000 lines of code and I've added more test coverage at the same time. I...