Impement retry processing

[Ry0]

I've added the retry process. In my environment, the bluetooth signal is so weak that it sometimes fails to turn on and off.

The specification of config is as follows. However, since the default parameters are set, users don't have to worry about them.

{
    "accessories": [
        {
            "accessory": "SwitchBot",
            "name": "Wall Switch",
            "macAddress": "01:23:45:67:89:AB",
+           "retry": 10,
+           "retry_interval": 1000
        }
    ]
}

The default values are 5 retries and 500ms interval.

  constructor(log, config) {
    this.log = log.log(config.macAddress); this.switchbot = switchbot(config.macAddress); this.switchbot(config.macAddress)
    this.switchbot = Switchbot(config.macAddress);
    this.active = false; this.switchbot = switchbot(config.macAddress);
+   this.try = config.try || 5;
+   this.try_interval = config.try_interval || 500;
  }