Releasing pylexibank

Do platform test via tox:

tox -r

Make sure flake8 passes:

flake8 src

Update the version number, by removing the trailing .dev0 in:
- setup.cfg
- src/pylexibank/__init__.py
In CHANGELOG.md, move the changes under the Unreleased heading to a new section with the new version number as its heading.
Create the release commit:

git commit -a -m "release <VERSION>"

Create a release tag:

git tag -a v<VERSION> -m"<VERSION> release"

Release to PyPI:

rm dist/*
python -m build -n
twine upload dist/*

Push to github:

git push origin
git push --tags

Increment version number and append .dev0 to the version number for the new development cycle:
- src/pylexibank/__init__.py
- setup.cfg
Commit/push the version change:

git commit -a -m "bump version for development"
git push origin