Level up private package generation

Biggest win is package.json [publishConfig](https://www.npmjs.org/doc/files/package.json.html#publishconfig), preventing us from publishing private modules anywhere but our private registry.

Other win is test coverage.  Especially around the most critical piece, spacing between badges in README.md!

Fixes #13, although I'm not sure about the CODE_OF_CONDUCT part.  I think it's meant to apply to open source projects, but doesn't seem harmful to leave it in. Strong feelings?

PS, have you all see [scoped packages](https://github.com/npm/npm/issues/5239) coming in npm 1.5?  @goodeggs/module-name always forwards to a configured private repo! :balloon: