0.22.1 bugfix release

Datasette 0.22: Datasette Facets

Release Datasette 0.21

Added Datasette 0.20 to news

Datasette 0.19: plugin preview (with release notes)

Releasing v0.18 - support for units!

Refs simonw#203

Release 0.17 to fix issues with PyPI

See https://twitter.com/simonw/status/984862976447414272

Releasing v0.16

Releasing v0.15

Releasing v0.14