Update version and changelog for 9.21.0 release (bvaughn#1252)

* update version and changelog

* fix package.json

Updating version to 9.20.1

update version to 9.20.0

Update version to 9.19.1

Update version to 9.19.0

9.18.5 release

9.18.3 release

9.18.2 release

9.18.1 release