Homebridge mqttthing securitySystem
Hi!

How should I configure my homebridge plugin when `MQTT_HOMEBRIDGE_ENABLE=True`?

I tried 

```javascript
 {
    "accessory": "mqttthing",
    "type": "securitySystem",
    "name": "Alarm",
    "url": "<url>",
    "username": "<user>",
    "password": "<password>",
    "topics": {
        "setTargetState": "paradox/control/partitions/Area_1/target",
        "getTargetState": "paradox/control/partitions/Area_1/current",
        "getCurrentState": "paradox/control/partitions/Area_1/current"
    },
    "targetStateValues": [
        "STAY_ARM",
        "AWAY_ARM",
        "NIGHT_ARM",
        "DISARM"
    ],
    "currentStateValues": [
        "STAY_ARM",
        "AWAY_ARM",
        "NIGHT_ARM",
        "DISARM",
        "Triggered"
    ]
}
```

But it seems like it doesn't work well when I manually enable/disable the alarm system.

Any clues? Maybe we should add an example in the wiki?