Using SBT Native Packager to build a zip

Didn't want to have to put SBT on a "prod" box, so this is what I came up with.

Generate the distributable with `sbt universal:packageBin`
 
After unzipping the distributable, note directories `bin/` `conf/` and `lib/` exist.
Place a suitable `account.config` into the `conf` directory.
Run with `bin/soymilky`

In our "prod" environment, I've got it reading utterances from a suitably-configured Dropbox directory so changes to the Dropboxed utterances file should show up straight away.