* Make several changes in the release and CI setup.
- Remove .travis/ directory completely.
- Update deploy.py script to tag with major.minor version
and remove the v in the tag which it didn't before.
- Fix the CircleCI cron setup.
* Update config.yml
* Use buildkit if possible.
* Use machine executor which supports buildkit.
* Remove setup docker step
* Use newer image.
* Use buildkit syntax for caching pip dependencies.
This should significantly speed up the build process by not having
to build python wheels multiple times.
* Use plain output from buildkit
* Make deploy script work with Python 2.7
Also cache python deps across builds.
* Fix more python3 things
* Install dependency in python3
