安装 TensorFlow object_detection

参考官方文档：https://tensorflow.google.cn/hub/tutorials/tf2_object_detection

以下为安装脚本：

git clone https://github.com/tensorflow/models.git
cd models/research
protoc object_detection/protos/*.proto --python_out=.
cp object_detection/packages/tf2/setup.py .
python -m pip install --use-feature=2020-resolver .