Train from --data path/to/dataset.zip feature (#4185)

* Train from `--data path/to/dataset.zip` feature

* Update dataset_stats()

* cleanup

* cleanup2

hubconf.py

@@ -27,7 +27,7 @@ def _create(name, pretrained=True, channels=3, classes=80, autoshape=True, verbo
 
     from models.yolo import Model, attempt_load
     from utils.general import check_requirements, set_logging
-    from utils.google_utils import attempt_download
+    from utils.downloads import attempt_download
     from utils.torch_utils import select_device
 
     file = Path(__file__).absolute()