Publish tag process

The new process is this:

1. `npm version minor` (or `prerelease` or whatever): Bumps the version number, creates git tag, etc.
2. `make publish`: This will publish that version as `--tag=v2.0.next` or `--tag=v1.4.next` as appropriate.
3. At some point later, `make tag`.  This will tag the current `v1.4.next` as "latest"

Review plz @othiym23