CVPR 2021 Argoverse-HD dataset autodownload support (#2400)

* added argoverse-download ability

* bugfix

* add support for Argoverse dataset

* Refactored code

* renamed to argoverse-HD

* unzip -q and YOLOv5

small cleanup items

* add image counts

Co-authored-by: Kartikeya Sharma <kartikes@trinity.vision.cs.cmu.edu>
Co-authored-by: Kartikeya Sharma <kartikes@trinity-0-32.eth>
Co-authored-by: Glenn Jocher <glenn.jocher@ultralytics.com>

data/argoverse_hd.yaml

@@ -0,0 +1,21 @@
+# Argoverse-HD dataset (ring-front-center camera) http://www.cs.cmu.edu/~mengtial/proj/streaming/
+# Train command: python train.py --data argoverse_hd.yaml
+# Default dataset location is next to /yolov5:
+#   /parent_folder
+#     /argoverse
+#     /yolov5
+
+
+# download command/URL (optional)
+download: bash data/scripts/get_argoverse_hd.sh
+
+# train and val data as 1) directory: path/images/, 2) file: path/images.txt, or 3) list: [path1/images/, path2/images/]
+train: ../argoverse/Argoverse-1.1/images/train/  # 39384 images
+val: ../argoverse/Argoverse-1.1/images/val/  # 15062 iamges
+test: ../argoverse/Argoverse-1.1/images/test/  # Submit to: https://eval.ai/web/challenges/challenge-page/800/overview
+
+# number of classes
+nc: 8
+
+# class names
+names: [ 'person',  'bicycle',  'car',  'motorcycle',  'bus',  'truck',  'traffic_light',  'stop_sign' ]