We automatically push tags to Rubygems via CI.

Release

Make sure you're on the latest master
Bump the version in version.rb
Update History.md
Commit these changes. git commit -am "Release x.y.z."
Tag the release. git tag -a -m "Version x.y.z" x.y.z
`git push -u origin master && git push --tags
Run the publish action on Github