Merge bitcoindevkit/bdk#852: Bump version to 0.27.0

Merge bitcoindevkit/bdk#852: Bump version to 0.27.0

0c2570ae07e7e90b66b2161121718ffac38dc3aa Pin dev-dependency zip to 0.6.3 (Steve Myers)
e83bb7c4dccd94d5876dc4361bd64c8405cf9f93 Bump version to 0.27.0 (Steve Myers)

Pull request description:

  ### Description

  Bump version to 0.27.0.

  ### Notes to the reviewers

  Updating changelog file again.

  ### Checklists

  #### All Submissions:

  * [x] I've signed all my commits
  * [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk/blob/master/CONTRIBUTING.md)

ACKs for top commit:
  danielabrozzoni:
    ACK 0c2570ae07e7e90b66b2161121718ffac38dc3aa

Tree-SHA512: 334e0a6933be18152f266e3622b877ccf67dafadd3a641eaf9ffa4e671babafbedcdaef431e2195aa7e11945f164b8da44bd8a208c8e7287ce87684fb2459787