message: v2.2.1 change log updates
  I forgot to commit changes after unsuccessful v2.2 release.
diff: @@ -8,9 +8,9 @@ This change log follows the format documented in [Keep a CHANGELOG].
  [semantic versioning]: http://semver.org/
  [keep a changelog]: http://keepachangelog.com/
  -## [2.2.0] - 2019-09-12
  +## [2.2.1] - 2019-09-12
  -Kudos to date-fns contributors: [@mzgajner](https://github.com/mzgajner), [@sibiraj-s](https://github.com/sibiraj-s), [@mukeshmandiwal](https://github.com/mukeshmandiwal) and [@SneakyFish5](https://github.com/SneakyFish5) and [@CarterLi](https://github.com/CarterLi).
  +Kudos to date-fns contributors: [@mzgajner](https://github.com/mzgajner), [@sibiraj-s](https://github.com/sibiraj-s), [@mukeshmandiwal](https://github.com/mukeshmandiwal), [@SneakyFish5](https://github.com/SneakyFish5) and [@CarterLi](https://github.com/CarterLi).
  ### Added
  