code: function toSemver(tag) {
      var parts = tag.split('.');
      var version = parts.slice(0, 3).join('.');
      var prerelease = Number(parts[3]);
  
      // semver == windows version
      if (!prerelease) return version;
  
      var channelId = Math.floor(prerelease/CHANNEL_MAGINITUDE);
      var channel = CHANNELS[channelId - 1];
      var count = prerelease - (channelId*CHANNEL_MAGINITUDE);
  
      return version + '-' + channel + '.' + count
  }
docs: Map a windows version to a semver