Release process

See if there are any PRs worth squeezing into release.
Go through the changes since last release, add them to changelog.
Add any new authors to the AUTHORS file.
If there's a new Salt release(major), update the script to add support for it.
Bump version for release
Open PR against develop with these changes.
Once the above PR is merged, open a PR against master with the changes from develop
Open a PR against salt with the new stable release.
Open a PR against kitchen-salt with the new stable release.