4.0.0.pre3 release?!

Changes in this commit include the version bump and CHANGELOG updates.

When we're set to release, here's actually a few additional steps we'll want to do:

* [ ] Release furoshiki 0.3.0
* [ ] Update our gemspec to use new furoshiki and remove from Gemfile (could probably add that on here, but wanted to get this posted for review!)
* [ ] Merge this PR
* [ ] Release the shoooooooes!
* [ ] Since we've got new gems, update the owners on the new gems
* [ ] Send message to mailing list
* [ ] Blog post
* [ ] :tada: :bell: :triumph: