Add rain total to grouped API

Weather/Service/Data/Resources/GetReadingHistoryGrouped.sql

@@ -3,7 +3,8 @@ SELECT bucket,
 	   AVG(Humidity) AS AverageHumidity,
        AVG(PressureTemperature) AS AveragePressureTemperature,
        AVG(Pressure) AS AveragePressure,
-	   AVG(LightLevel) AS AverageLightLevel
+	   AVG(LightLevel) AS AverageLightLevel,
+       SUM(Rain) AS RainTotal
 FROM (
          SELECT CAST(FORMAT(Timestamp, 'yyyy-MM-ddTHH:') +
                 RIGHT('00' + CAST(DATEPART(MINUTE, Timestamp) / @BucketMinutes * @BucketMinutes AS VARCHAR), 2)
@@ -12,7 +13,8 @@ FROM (
 				Humidity,
 				PressureTemperature,
 				Pressure,
-				LightLevel / BatteryLevel AS LightLevel
+				LightLevel / BatteryLevel AS LightLevel,
+                Rain
          FROM Reading
          WHERE Timestamp BETWEEN @Start AND @End
      ) AS Data

Weather/Service/Models/WeatherReadingGrouped.cs

@@ -17,5 +17,7 @@ namespace ChrisKaczor.HomeMonitor.Weather.Service.Models
         public decimal AveragePressure { get; set; }
 
         public decimal AverageLightLevel { get; set; }
+
+        public decimal RainTotal { get; set; }
     }
 }