v0.21.0

Bump to 0.20.1 (#1216)

github/workflows/upload-to-pypi: install setuptools

We should probably move to setup.cfg at some point, but not today.

Bump version to 0.19.0 (#1124)

Bump 0.18.1 (#1061)

Bump version to 0.18.0, add changelog (#1046)

Bump version to 0.17.0 (#964)

setup: bump to 0.16.0

setup: bump to 0.15.0

setup: bump to 0.14.0