message: chore: changelog for v0.29.0
diff: +# [v0.29.0](https://github.com/nervosnetwork/ckb/compare/v0.28.0...v0.29.0) (2020-02-26)
  +
  +### Breaking Changes
  +
  +* #1928: Null outputs_validator means passthrough. (@doitian)
  +
  + The default behavior is incompatible with v0.28.0, but is compatible with v0.27.1 and older versions.
  +
  # [v0.28.0](https://github.com/nervosnetwork/ckb/compare/v0.27.0...v0.28.0) (2020-01-31)
  ### Breaking Changes
  