feat: add AIPlayer with takeTurn() method

Intention is the game hands control to AI player after human ends turn by
calling this method

app/structures/basic/AIPlayer.java

@@ -0,0 +1,41 @@
+package structures.basic;
+
+// import basic commands for notifications
+import commands.BasicCommands;
+import structures.GameState;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+
+import akka.actor.ActorRef;
+
+public class AIPlayer extends Player {
+    public AIPlayer() {
+        super();
+    }
+
+    public void takeTurn(ActorRef out, GameState gameState) {
+        // addPlayer2Notification
+        BasicCommands.addPlayer2Notification(out, "My turn!", 2);
+        // addPlayer2Notification
+        BasicCommands.addPlayer2Notification(out, "Ending turn", 2);
+        // send "endTurnClicked" message to GameActor
+        // NOTE: #query -- how do we get the GameActor reference?
+        // #hack way- we add a reference to the GameActor in GameState
+        // first create the "endTurnClicked" message:
+        JsonNode message = new ObjectMapper().createObjectNode();
+        ((ObjectNode) message).put("messageType", "endTurnClicked");
+        // add some content to say it is the AI player who 'clicked' end turn:
+        ((ObjectNode) message).put("player", "AI");
+        // then send it to the GameActor:
+        try {
+            gameState.gameActor.processMessage("endturnclicked", message);
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        // gameState.gameActor.receive(message);
+
+    }
+
+}