message: remove beta and add date
diff: @@ -6,7 +6,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
  ## Unreleased
  -## [21.0.0-beta.1]
  +## [21.0.0] - 2020-01-17
  ### Added
  - More Blockstack error codes.
  - `putFile` and `encryptContent` can now optionally base64 encode data, for a ~33% size increase compared to the default hex encoding which has a 100% size increase.
  