Update Changelog
  rm Changelog && make Changelog
Update NEWS (see Changelog)
COL_VERSION=0.9.1
change version number in lib/columnize/version.rb
  VERSION = '0.9.1'
rake test
sudo rake install
rake package (and look at package)
echo git tag release-${COL_VERSION}
  and then do it
git push --tags

Copy gem to another machine, install and test!

gem push pkg/columnize-${COL_VERSION}.gem
change version number in lib/columnize/version.rb
  VERSION = '0.9.1.dev
