Update .dockerignore, .gitattributes, .gitignore, CONTRIBUTING.md, detect.py,...

Update .dockerignore, .gitattributes, .gitignore, CONTRIBUTING.md, detect.py, Dockerfile, export.py, hubconf.py, LICENSE, model.properties, native bn.png, pycoco_false_result.png, pycocotools.png, README.md, requirements.txt, train.py, tutorial.ipynb, val.py, view_code.py, data/Argoverse.yaml, data/coco.yaml, data/coco128.yaml, data/GlobalWheat2020.yaml, data/Objects365.yaml, data/SKU-110K.yaml, data/VisDrone.yaml, data/VOC.yaml, data/xView.yaml, data/hyps/hyp.finetune.yaml, data/hyps/hyp.finetune_objects365.yaml, data/hyps/hyp.scratch.yaml, data/hyps/hyp.scratch-high.yaml, data/hyps/hyp.scratch-low.yaml, data/images/bus.jpg, data/images/zidane.jpg, data/scripts/download_weights.sh, data/scripts/get_coco.sh, data/scripts/get_coco128.sh, models/__init__.py, models/common.py, models/experimental.py, models/tf.py, models/yolo.py, models/yolov5l.yaml, models/yolov5m.yaml, models/yolov5n.yaml, models/yolov5s.yaml, models/yolov5x.yaml, models/hub/anchors.yaml, models/hub/yolov3.yaml, models/hub/yolov3-spp.yaml, models/hub/yolov3-tiny.yaml, models/hub/yolov5-bifpn.yaml, models/hub/yolov5-fpn.yaml, models/hub/yolov5l6.yaml, models/hub/yolov5m6.yaml, models/hub/yolov5n6.yaml, models/hub/yolov5-p2.yaml, models/hub/yolov5-p6.yaml, models/hub/yolov5-p7.yaml, models/hub/yolov5-panet.yaml, models/hub/yolov5s6.yaml, models/hub/yolov5s-ghost.yaml, models/hub/yolov5s-transformer.yaml, models/hub/yolov5x6.yaml, utils/__init__.py, utils/activations.py, utils/augmentations.py, utils/autoanchor.py, utils/callbacks.py, utils/datasets.py, utils/downloads.py, utils/general.py, utils/loss.py, utils/metrics.py, utils/plots.py, utils/torch_utils.py, utils/aws/__init__.py, utils/aws/mime.sh, utils/aws/resume.py, utils/aws/userdata.sh, utils/flask_rest_api/example_request.py, utils/flask_rest_api/README.md, utils/flask_rest_api/restapi.py, utils/google_app_engine/additional_requirements.txt, utils/google_app_engine/app.yaml, utils/google_app_engine/Dockerfile, utils/loggers/__init__.py, utils/loggers/wandb/__init__.py, utils/loggers/wandb/log_dataset.py, utils/loggers/wandb/README.md, utils/loggers/wandb/sweep.py, utils/loggers/wandb/sweep.yaml, utils/loggers/wandb/wandb_utils.py files

utils/aws/mime.sh

+# AWS EC2 instance startup 'MIME' script https://aws.amazon.com/premiumsupport/knowledge-center/execute-user-data-ec2/
+# This script will run on every instance restart, not only on first start
+# --- DO NOT COPY ABOVE COMMENTS WHEN PASTING INTO USERDATA ---
+
+Content-Type: multipart/mixed; boundary="//"
+MIME-Version: 1.0
+
+--//
+Content-Type: text/cloud-config; charset="us-ascii"
+MIME-Version: 1.0
+Content-Transfer-Encoding: 7bit
+Content-Disposition: attachment; filename="cloud-config.txt"
+
+#cloud-config
+cloud_final_modules:
+- [scripts-user, always]
+
+--//
+Content-Type: text/x-shellscript; charset="us-ascii"
+MIME-Version: 1.0
+Content-Transfer-Encoding: 7bit
+Content-Disposition: attachment; filename="userdata.txt"
+
+#!/bin/bash
+# --- paste contents of userdata.sh here ---
+--//

utils/google_app_engine/additional_requirements.txt

+# add these requirements in your app on top of the existing ones
+pip==19.2
+Flask==1.0.2
+gunicorn==19.9.0