BasicServiceSets.Bssid incosistent property type

For some devices the [Device Wireless Status](https://developer.cisco.com/meraki/api-v1/get-device-wireless-status/) endpoint returns basicServiceSets.bssid as a string, but for some devices bssid is an object:

```
"bssid": {
    "mac_address": "1a:2b:3c:00:00:00",
    "enabled": true
},
```

