This repo lacks a LICENSE, COPYING, or licence header on files but the [package.json](https://github.com/Simperium/node-simperium/blob/986ce2a7d688dd249c346626dce76d292e01c684/package.json#L25) says `BSD-2-Clause`, is that accurate? Any chance [a licence file could be added](https://help.github.com/en/github/building-a-strong-community/adding-a-license-to-a-repository)?