Improve Appveyor config
Improve Appveyor config

- make wrapper cache dependent on wrapper version
- make Conda setup quieter

martinlaz/lenskit,blankazucenalg/lenskit,blankazucenalg/lenskit,vaibhav345/lenskit,kluver/lenskit,tajinder-txstate/lenskit,kluver/lenskit,linjunleo/lenskit,tajinder-txstate/lenskit,kluver/lenskit,tajinder-txstate/lenskit,vaibhav345/lenskit,binweiwu/lenskit,martinlaz/lenskit,binweiwu/lenskit,vaibhav345/lenskit,vaibhav345/lenskit,kluver/lenskit,amaliujia/lenskit,chrysalag/lenskit,tajinder-txstate/lenskit,chrysalag/lenskit,linjunleo/lenskit,amaliujia/lenskit,kluver/lenskit