message: updated changelog to 4.3
diff: +## 4.3 Nov 1, 2017
  +
  +- Switched from using _in-house_ Zip implementation to `yazl` and refactored `Pass.pipe` for simplier form using `async` function.
  +
  ## 4.2 Nov 1, 2017
  - switched from our fork of `node-apn` to native HTTP2 implementation from Node 8.8 LTS.
  +- don't compress any file, just store inside of Zip, so, it suppose to be faster and more compatible
  ## 4.1 October 14, 2017
  