Create a websocket client and set it off at the server
@method  createClient
@private
@param   {string} host Hostname
@param   {integer} port Port number
@param   {integer} concurrent Number of clients to spin up
@param   {integer} frequency Amount of time, in ms, to wait between emitting messages
@param   {integer} duration Amoutn of time, in ms, to run each client for
@param   {object} gen The generator object, required and parse
@param   {integer} iteration What client number you're on
@returns {object} undefined
function createClient (host, port, concurrent, frequency, duration, gen, iteration) {
  var auth = defaults.auth
  var getMessage = defaults.getMessage
  emitter.emit('start')

  if (typeof gen.authenticate === 'function') {
    auth = gen.authenticate
  }

  if (typeof gen.clientIterateMessage === 'function') {
    getMessage = gen.clientIterateMessage
  }

  /**
   * Once auth is complete, this actually initiates the client
   * @method  postAuth
   * @async
   * @private
   * @param   {object} err Error from auth, if any
   * @param   {object} cookies Any cookies to pass through to the socket object
   * @param   {string} user The username used to login
   * @param   {string} pass The password used to login
   * @returns {object} undefined
   */
  var postAuth = function (err, cookies, user, pass) {
    ++clientsAttempted
    if (err) {
      emitter.emit('error', err)
      if (clientsAttempted === concurrent && _intervals.length === 0) {
        emitter.emit('end')
      }
      return
    }

    var socketUrl = gen.getSocketURL(host, port, cookies, user, pass) || host + ':' + port
    var socket = io(socketUrl, { multiplex: false })
      .on('connect', function () {
        emitter.emit('client-connected')
        if (typeof gen.events.connect === 'function') {
          gen.events.connect('connect', cookies, user, pass, {}, socket, emitter)
        }

        Object.keys(gen.events).forEach(function (eventName) {
          socket.on(eventName, function (data) {
            gen.events[eventName].call(null, eventName, cookies, user, pass, data, socket, emitter)
          })
        })

        var sendMessage = function () {
          var message = getMessage(cookies, user, pass)
          if (!Array.isArray(message)) {
            message = [message]
          }

          for (var i = 0, len = message.length; i < len; i++) {
            if (message[i]) {
              socket.json.send(message[i])
              emitter.emit('message', message[i])
            }
          }
        }

        _intervals.push(setInterval(sendMessage, frequency))

        setTimeout(function () {
          clearInterval(_intervals.pop())
          socket.emit('disconnect')
          emitter.emit('disconnect')
          socket.close()
          if (_intervals.length === 0) {
            done()
          }
        }, duration)
      })
      .on('connect_error', function (err) {
        emitter.emit('error', err)
        if (clientsAttempted === concurrent && _intervals.length === 0) {
          emitter.emit('end')
        }
      })
  }

  auth(host, port, iteration, postAuth)
}