[file-static-server] Path Traversal allows to read content of arbitrary file on the server

There is Path Traversal vulnerability in file-static-server module, which allows to read arbitrary file from the remote server.

// ./node_modules/file-static-server/lib/file.js, line 21:
getFilePath: function () {
    if (this.filePath) {
      return this.filePath
    }
    var url = this.req.url
    var len = process.argv.length
    this.filePath = path.join(process.argv[len - 1], url)
    return this.filePath
  },