feat: add unit test

hamster_tycoon/hamster.go

@@ -3,7 +3,7 @@ package hamster_tycoon
 import (
 	"errors"
 	"fmt"
-	"math/rand"
+	"hamster-tycoon/randomizer"
 )
 
 const (
@@ -56,7 +56,7 @@ func (h *Hamster) Fuck(another *Hamster) (bool, error) {
 		return false, errors.New("can't fuck together")
 	}
 
-	if h.Age <= GestationMinAge || another.Age <= GestationMinAge {
+	if h.Age < GestationMinAge || another.Age < GestationMinAge {
 		return false, errors.New("one of the hamster is too young")
 	}
 
@@ -128,5 +128,5 @@ func randSexe() string {
 }
 
 func randNumber(min int, max int) int {
-	return min + rand.Intn(max-min)
+	return min + randomizer.Rand(max-min)
 }