Percentile aggregator fails on my maching due to issues converting double.

My locale expects doubles to be in the 1,0 format, so the double.parse
fails if it tries to parse 1.0.
Added CultureInfo.InvariantCulture to the parse to fix this.

Author: andersosthus

Diff for: src/Nest/Resolvers/Converters/Aggregations/AggregationConverter.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Linq;
 using System.Text.RegularExpressions;
 using Newtonsoft.Json;
@@ -69,7 +70,7 @@ private IAggregation GetPercentilesMetricAggregation(JsonReader reader, JsonSeri
 				reader.Read();
 			while (reader.TokenType != JsonToken.EndObject)
 			{
-				var percentile = double.Parse(reader.Value as string);
+				var percentile = double.Parse(reader.Value as string, CultureInfo.InvariantCulture);
 				reader.Read();
 				var value = reader.Value as double?;
 				percentileItems.Add(new PercentileItem()