2.15.0

What's Changed

• lightning: copy best model by @dberenbaum in #659
• fix broken pytorch-lightning import by @dberenbaum in #664
• HuggingFace improvements by @daavoo in #649
• cache: cache in dvc exp if not stage output by @dberenbaum in #660

Full Changelog: 2.14.0...2.15.0