message: Improve ping pong test, swoole websocket client support send ping frame and recv pong frame.
diff: swoole_websocket_server: websocket push 2
  --SKIPIF--
  <?php require __DIR__ . '/../include/skipif.inc'; ?>
  ---INI--
  -assert.active=1
  -assert.warning=1
  -assert.bail=0
  -assert.quiet_eval=0
  -
  --FILE--
  <?php
  require_once __DIR__ . '/../include/bootstrap.php';
  -require __DIR__ . '/../include/swoole.inc';
  -require __DIR__ . '/../include/lib/class.websocket_client.php';
  -
  -function start_swoole_ws_server()
  +$pm = new ProcessManager;
  +$pm->parentFunc = function (int $pid) use ($pm) {
  + go(function () use ($pm) {
  + $cli = new \Swoole\Coroutine\Http\Client('127.0.0.1', $pm->getFreePort());
  + $cli->set(['timeout' => 1]);
  + $ret = $cli->upgrade('/');
  + assert($ret);
  + for ($i = 100; $i--;)
  {
  - swoole_php_fork(function ()
  - {
  - $serv = new swoole_websocket_server("127.0.0.1", 9501);
  - $serv->set(['log_file' => '/dev/null']);
  - $serv->on('Open', function ($swoole_server, $req)
  - {
  - });
  -
  - $serv->on('Message', function ($swoole_server, $frame)
  - {
  - $swoole_server->push($frame->fd, "hello " . $frame->data);
  + $ping = new swoole_websocket_frame;
  + $ping->opcode = WEBSOCKET_OPCODE_PING;
  + $ret = $cli->push($ping);
  + assert($ret);
  + $pong = $cli->recv();
  + assert($pong->opcode == WEBSOCKET_OPCODE_PONG);
  + }
  + $pm->kill();
  });
  -
  - $serv->on('Close', function ($swoole_server, $fd)
  - {
  + swoole_event_wait();
  +};
  +$pm->childFunc = function () use ($pm) {
  + $serv = new swoole_websocket_server("127.0.0.1", $pm->getFreePort());
  + $serv->set([
  + 'worker_num' => 1,
  + 'log_file' => '/dev/null'
  + ]);
  + $serv->on('workerStart', function () use ($pm) {
  + $pm->wakeup();
  });
  -
  + $serv->on('open', function ($swoole_server, $req) { });
  + $serv->on('message', function ($swoole_server, $frame) { });
  + $serv->on('close', function ($swoole_server, $fd) { });
  $serv->start();
  - });
  -}
  -sleep(1); //wait the release of port 9501
  -start_swoole_ws_server();
  -sleep(1);
  -
  -$cli = new WebsocketClient;
  -$connected = $cli->connect('127.0.0.1', 9501, '/');
  -echo $cli->checkConnection(),"\n";
  +};
  +$pm->childFirst();
  +$pm->run();
  ?>
  -Done
  ---EXPECTREGEX--
  -1
  -Done.*
  ---CLEAN--
  +--EXPECT--
  