Add code style support for Python about emblem

[dinagraves]

We use the following flake8 args in python-docs-samples. https://github.com/GoogleCloudPlatform/python-docs-samples/blob/master/noxfile-template.py#L131

I don't know if there is a way to make flake8 automatically fix the style and import issues it finds. If we want to do that, we might want to use black for the linting and isort with autoflake for the imports.

[ace-n]

(Also: we may be able to use black for local linting and perform the rest via GitHub Actions.)