refactoring: add player to card

src/main/java/de/hsfulda/onses/models/Card.java

@@ -16,6 +16,8 @@ public class Card {
     private boolean facedown = false;
     private boolean selected;
 
+    private Player player;
+
     public enum Color {
         RED, BLUE, GREEN, YELLOW, BLACK;
     };
@@ -65,6 +67,15 @@ public class Card {
         return this;
     }
 
+    public Player getPlayer() {
+        return player;
+    }
+
+    public Card setPlayer(Player player) {
+        this.player = player;
+        return this;
+    }
+
     public PropertyChangeSupport listeners() {
         if(this.listeners == null) {
             this.listeners = new PropertyChangeSupport(this);