parseNumbers ignored with arrayFormat

[chapmanio]

The parseNumbers option does not get applied to values in an array. e.g.:

const query = queryString.parse('?arrayOfNumbers=15,16,17&singleNumber=18', {
  parseNumbers: true,
  arrayFormat: 'comma',
});

Produces:

{
  arrayOfNumbers: ["15", "16", "17"],
  singleNumber: 18,
}

I was expecting it to produce:

{
  arrayOfNumbers: [15, 16, 17],
  singleNumber: 18,
}

[sindresorhus]

// @yaodingyd