Chapter 18: cannot import name 'naming' from 'tensorflow.python.autograph.core'

Hi,

I've been trying to make the TF-Agents examples work on my machine and I keep getting this error which I can't seem to find a solution for (went on Tensorflow's github repo to search for issues and at a surface level nothing seemed to match what I had).

The error is the following :
```ImportError: cannot import name 'naming' from 'tensorflow.python.autograph.core' (/home/quoding/AI/ai_venv/lib/python3.7/site-packages/tensorflow/python/autograph/core/__init__.py)```

This error happens when importing with this line: `from tf_agents.environments import suite_atari`

I have installed the Python packages in the following manner : `pip install -r requirements.txt` with the `requirements.txt` file provided in this repo.

If it is worth noting, the error happens in the Notebook as well as in an editor with only the code.

I'll keep looking for a workaround, but any help is appreciated.