fix: Set correct decimal separator symbol

Necessary in order to fix issues related to different
locales at different machines. This was discovered
when tests failed at one laptop and not another.

src/main/java/no/nibio/model/maizepheno/MaizePhenologyModel.java

@@ -20,6 +20,7 @@
 package no.nibio.model.maizepheno;
 
 import java.text.DecimalFormat;
+import java.text.DecimalFormatSymbols;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
@@ -28,6 +29,7 @@ import java.util.Collections;
 import java.util.Date;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Set;
 import java.util.TimeZone;
 import java.util.stream.Collectors;
@@ -84,7 +86,10 @@ public class MaizePhenologyModel extends I18nImpl implements Model{
         Date lastDate = this.dataMatrix.getLastDateWithParameterValue(DataMatrix.TND);
         Double heatSum = 0.0;
         List<Result> retVal = new ArrayList<>();
-        DecimalFormat dFormat = new DecimalFormat("###.##");
+
+        DecimalFormatSymbols symbols = new DecimalFormatSymbols(Locale.getDefault());
+        symbols.setDecimalSeparator('.');
+        DecimalFormat dFormat = new DecimalFormat("###.##", symbols);
         while(!currentDate.after(lastDate))
         {
             Result result = new ResultImpl();