function parseFile (filename, fn) {
  fs.readFile(filename, { encoding: 'utf8' }, onread);
  function onread (err, inxml) {
    if (err) return fn(err);
    parse.parseString(inxml, fn);
  }
}
Parses file `filename` as a .plist file.
Invokes `fn` callback function when done.

@param {String} filename - name of the file to read
@param {Function} fn - callback function
@api public
@deprecated use parseString() instead