Build out some release automation

[arrdem]

Right now, my releases of Katamari to Github are entirely manual. It shouldn't be too hard to build a Katamari CI job on CircleCI which for any given branch attempts to re-bootstrap Katamari using source paths and then again using the produced bootstrap jar. There should also be some other end-to-end tests at that level which run.

Given that success, an automated release could be tagged and pushed.
Or at the least I could have an etc/release.sh which automates patching and committing the kat script version bump and uploading both the script and the standalone jar to Github.