Run the command as well as another check.

Workaround missing imported packages in some cases (like pre-commit) so
the module can still be imported.

The Python snippet.

empty.

Don't ship a requirements.txt file with locked versions of packages just
for the Docker image. The test don't include the dependencies anyway so
there's no point and without hashes there's no security benefits.
Instead use bump-version to update the version in the Docker image and
remove hashin package and the update-reqs pipenv script.

- Added check-manifest pre-commit hook.
- Implement suggestions from check-manifest.

- Just install from PyPI.
- Pin versions and hashes.
- Use hashin to generate requirements.txt.
- Add Pipfile scripts entry to update requirements.txt.

bucket.

- Also, replaced dateutil with pytz.
- And use prefix instead of regex (as does S3).
- Added more sanity checks (like is the file timestamp from the future,
empty files, etc.).

- Use Pipenv for local development tasks in a virtualenv.
- Replace fabfile with Pipfile "scripts".
- Update .gitignore.
- Add lots of checks using pre-commit.
- Format code using Black.
- Use PEP 396 version tracking.
- Use bumpversion for tagging new versions.
- Fix issues found with Flake8, pylint.