Use __all__ in __init__.py

[sobolevn]

What was wrong?

Mypy was raising "undefined name" with --no-implicit-reexport flag.

How was it fixed?

Defining __all__ is good enough.
It also allows to remove noqa from flake8.

Cute Animal Picture

[sobolevn]

This looks unrelated: https://circleci.com/gh/ethereum/eth-typing/495?utm_campaign=vcs-integration-link&utm_medium=referral&utm_source=github-build-link

Extension error:
Could not import extension sphinx.builders.latex (exception: cannot import name 'contextfunction' from 'jinja2' (/home/circleci/repo/.tox/doctest/lib/python3.8/site-packages/jinja2/__init__.py))
make: *** [Makefile:165: doctest] Error 2
make: Leaving directory '/home/circleci/repo/docs'
ERROR: InvocationError for command /usr/bin/make -C docs doctest (exited with code 2)
___________________________________ summary ____________________________________
ERROR:   doctest: commands failed


Exited with code exit status 1

[fselmo]

lgtm, thanks!