Topic name generation fails for DHW zone

[elguiri]

Hi Stephan @svrooij

Thanks for your efforts on the project. I just installed it today and have noticed a slight anomaly in the automatic mqtt topic name generation specifically for the DHW (hot water) zone (which I believe is a special case in the evohome system because it cannot be renamed by the user).

The topics created are:

evohome/status/thermostat/
evohome/status/thermostat//temp

That is, it looks like the DHW zone takes a zero length string as its name.

The status JSON for evohome/status/thermostat/ is:

{"val":51.03,"state":{"units":"Celsius","indoorTemperature":51.03,"allowedModes":["DHWOn","DHWOff"],"minHeatSetpoint":5,"maxHeatSetpoint":30,"changeableValues":{"mode":"DHWOn","status":"Scheduled"}},"lc":1537123696132}

Thanks

[elguiri]

I did a quick fix in the bridge.js file:

if (device.thermostat) {
    let name = device.name.toLowerCase();
    name = name.length == 0 ? "dhw" : name;

In my case (but not for everybody), I then went one step further and converted the thermostat name to camel case because I prefer not to see spaces in the mqtt topic:

const camelCase = require('camelcase');
...
if (device.thermostat) {
    let name = device.name.toLowerCase();
    name = name.length == 0 ? "dhw" : camelCase(name);