var client = webdriver.remote({
  desiredCapabilities: {
    browserName: 'phantomjs',
    proxy: {
      proxyType: 'manual',
      httpProxy: proxyServer.ipAddress + ':' + proxyServer.httpPort,
      socksUsername: proxyServer.username,
      socksPassword: proxyServer.password
    }
  }
});

var client = webdriver.remote({
  desiredCapabilities: {
    browserName: 'phantomjs',
    'phantomjs.cli.args': [
      '--proxy-type=http',
      '--proxy=' + proxyServer.ipAddress + ':' + proxyServer.httpPort,
      '--proxy-auth=' + proxyServer.username + ':' + proxyServer.password
    ].join(' ')
  }
});