[BREAKING] remove tem key (#883)

* [BREAKING] remove tem key

we rely now on tempc and tempf only

main/ZgatewayWeatherStation.ino

@@ -105,7 +105,6 @@ void sendTemperatureData(byte id, float temperature, int humidity, byte battery_
     StaticJsonBuffer<JSON_MSG_CALC_BUFFER> jsonBuffer;
     JsonObject& RFdata = jsonBuffer.createObject();
     RFdata.set("sensor", id);
-    RFdata.set("temperature", temperature); // remove for 0.9.6 release
     RFdata.set("tempc", temperature);
     RFdata.set("tempf", wsdr.convertCtoF(temperature));
     RFdata.set("humidity", humidity);