Added getSum methods to hand class

src/main/java/edu/ntnu/stud/cardgame/HandOfCards.java

@@ -2,6 +2,7 @@ package edu.ntnu.stud.cardgame;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.stream.Collectors;
 
 public class HandOfCards {
   private final List<PlayingCard> hand;
@@ -17,4 +18,10 @@ public class HandOfCards {
   public void addCard(PlayingCard card) {
     hand.add(card);
   }
+
+  public int getSum() {
+    return hand.stream().
+        mapToInt(PlayingCard::getFace).
+        sum();
+  }
 }