Issue with updating goldens

[alicejli]

Attempting to follow the steps here: https://github.com/googleapis/doc-pipeline#testing

1. The Docker instructions to:

Copy a service account with permission to access my-bucket to /dev/shm/73713_docuploader_service_account.

could be clarified / updated (not sure if we can still do this?)

and

2. The local instructions to:

black --check tests
flake8 tests
GOOGLE_APPLICATION_CREDENTIALS=/path/to/service-account.json TEST_BUCKET=my-bucket pytest tests

Internal users are no longer able to authenticate using a .json file per change in GCP policy.

When running python3 -m pytest --update-goldens tests, I get this error:

../../.pyenv/versions/3.9.0/lib/python3.9/subprocess.py:1819: FileNotFoundError

FAILED tests/test_generate.py::test_local_generate - Failed: build_local_doc raised an exception: [Errno 2] No such file or directory: 'docfx'
FAILED tests/test_goldens.py::test_goldens[dotnet] - FileNotFoundError: [Errno 2] No such file or directory: 'docfx'
FAILED tests/test_goldens.py::test_goldens[go] - FileNotFoundError: [Errno 2] No such file or directory: 'docfx'
FAILED tests/test_goldens.py::test_goldens[java] - FileNotFoundError: [Errno 2] No such file or directory: 'docfx'
FAILED tests/test_goldens.py::test_goldens[nodejs] - FileNotFoundError: [Errno 2] No such file or directory: 'docfx'
FAILED tests/test_goldens.py::test_goldens[php] - FileNotFoundError: [Errno 2] No such file or directory: 'docfx'
FAILED tests/test_goldens.py::test_goldens[python] - FileNotFoundError: [Errno 2] No such file or directory: 'docfx'
FAILED tests/test_goldens.py::test_goldens[ruby] - FileNotFoundError: [Errno 2] No such file or directory: 'docfx'

Updated instructions for running tests / updating goldens locally and/or using Docker would be greatly appreciated!

[tbpg]

docuploader can work with ADC. But, I don't know how to do that from inside Docker.