[DELF] missing setup.py for object_detection when running insall_delf.sh

Prerequisites

Please answer the following questions for yourself before submitting an issue.

• [ O] I am using the latest TensorFlow Model Garden release and TensorFlow 2.
• [ O] I am reporting the issue to the correct repository. (Model Garden official or research directory)
• [ O] I checked to make sure that this issue has not already been filed.

1. The entire URL of the file you are using

https://github.com/tensorflow/models/tree/master/research/delf/delf/python/training/install_delf.sh

2. Describe the bug

There is a bug in install_object_detection() of install_delf.sh. Because the "tensorflow/models" is updated and there is no "tensorflow/models/research/ setup.py" any more.

3. Steps to reproduce

Steps to reproduce the behavior.

4. Expected behavior

Recommend users to use "git clone -b archive ~" in the DELF install INSTRUCTION. Or use some better ways to solve this issue.

A clear and concise description of what you expected to happen.

5. Additional context

Include any logs that would be helpful to diagnose the problem.

6. System information

• OS Platform and Distribution (e.g., Linux Ubuntu 16.04):
• Mobile device name if the issue happens on a mobile device:
• TensorFlow installed from (source or binary):
• TensorFlow version (use command below):
• Python version:
• Bazel version (if compiling from source):
• GCC/Compiler version (if compiling from source):
• CUDA/cuDNN version:
• GPU model and memory: