Expand attribute output. #493 (#1277)

* Expand attribute output. #493

If attribute is actually an Object, expand it in the format `topic/key-subkey` in order to keep the same amount of topic levels for predictable parsing.
This only expands the first level of contained object. If more expansion are needed a more robust method should be implemented rather than just nesting `if`s.

* Fixing whitespace

fixing https://travis-ci.org/Koenkk/zigbee2mqtt/builds/507616980

* first time splitting line... obviously

Not sure what the proper approach is, but I guess we can put all params on new line.

* identation... really...

How is that `eslint`? any other requests?

lib/controller.js

@@ -245,7 +245,14 @@ class Controller {
             this.mqtt.publish(entity.friendlyName, JSON.stringify(messagePayload), options);
         } else if (settings.get().experimental.output === 'attribute') {
             Object.keys(messagePayload).forEach((key) => {
-                this.mqtt.publish(`${entity.friendlyName}/${key}`, JSON.stringify(messagePayload[key]), options);
+                if (typeof messagePayload[key] == 'object') {
+                    Object.keys(messagePayload[key]).forEach((subKey) => {
+                        this.mqtt.publish(`${entity.friendlyName}/${key}-${subKey}`,
+                            JSON.stringify(messagePayload[key][subKey]), options);
+                    });
+                } else {
+                    this.mqtt.publish(`${entity.friendlyName}/${key}`, JSON.stringify(messagePayload[key]), options);
+                }
             });
         }
     }