fix: Set correct first day of week, fix test accordingly

This setting may differ from machine to machine, so we need
to set it explicitly in order to ensure correct results.

src/main/java/no/nibio/vips/model/oatfloweringmodel/OatFloweringModel.java

@@ -122,6 +122,7 @@ public class OatFloweringModel extends I18nImpl implements Model{
     private Result initResult(WeatherObservation obs)
     {
         Calendar cal = Calendar.getInstance();
+        cal.setFirstDayOfWeek(Calendar.MONDAY);
         Result result = new ResultImpl();
         result.setValidTimeStart(obs.getTimeMeasured());
         

src/test/java/OatFloweringModelTest.java

@@ -119,7 +119,7 @@ public class OatFloweringModelTest {
                 System.out.println("Result: [" + result.getValidTimeStart() + "]" + result.getAllValues());
             }*/
             
-            assertEquals("27", weekResult);
+            assertEquals("26", weekResult);
             assertEquals("60", zReached);
             
         }