private fields for calculated values

goodcalc.go

@@ -9,8 +9,8 @@ package goodcalc
 type Aspect struct {
 	No                 string  `json:"no"`
 	Weight             float32 `json:"weight"`
-	MaxValuationPoints int     `json:"max_valuation_points"`
 	ValuationPoints    int     `json:"valuation_points"`
+	maxValuationPoints int
 }
 
 // NegativeAspect has the same fields like Aspect. But the