How I delete a zone...

deleteZone.js

var pkgcloud = require('pkgcloud'),
  log = require('../../common/logging'),
  _ = require('underscore'),
  config = require('../config');

var logger = log.getLogger('debug');

var client = pkgcloud.providers.rackspace.dns.createClient(config.getConfig(1));

client.on('log::*', log.logFunction);

client.deleteZone(process.argv[2], function (err) {
  console.dir(err);
});