function packagePortable (filesPath, cb) {
      console.log('Windows: Creating portable app...')

      const portablePath = path.join(filesPath, 'Portable Settings')
      fs.mkdirSync(portablePath, { recursive: true })

      const downloadsPath = path.join(portablePath, 'Downloads')
      fs.mkdirSync(downloadsPath, { recursive: true })

      const tempPath = path.join(portablePath, 'Temp')
      fs.mkdirSync(tempPath, { recursive: true })

      const inPath = path.join(DIST_PATH, path.basename(filesPath))
      const outPath = path.join(DIST_PATH, BUILD_NAME + '-win.zip')
      zip.zipSync(inPath, outPath)

      console.log('Windows: Created portable app.')
      cb(null)
    }
Delete extraneous Squirrel files (i.e. *.nupkg delta files for older
versions of the app)