Added toString() method for DEBUG purposes

src/main/java/no/bioforsk/vips/model/roughagenutritionmodel/OptimizationObservation.java

@@ -179,4 +179,15 @@ public class OptimizationObservation implements Comparable{
         this.FEm = FEm;
     }
 
+    @Override
+    public String toString(){
+        return "OptimizationObservation[" + this.getDate() + "] "
+                + "Yield = " + this.getAvling() 
+                + ", FEm = " + this.getFEm()
+                + ", Height = " + this.getHeight()
+                + ", INDF = " + this.getINDF()
+                + ", MSC = " + this.getMSC()
+                + ", NDF = " + this.getNDF()
+                + ", RawProtein = " + this.getRawProtein();
+    }
 }