Completed checkpoint 3

What I changed
(I gave the computer player the look ahead strategy. This also required importing LookaheadStrategy in player.py.
I also answered the questions in notes.md.)

Why I changed it
(I was working on completing checkpoint 3. I realized I had to do the importing since otherwise it wouldn't let me play.)

Estimate for remaining time to finish assignment: [I am REALLY bad at these estimates. I mean in terms of actual work time, I'm probably not too far off. Fingers crossed, maybe another hour of actual work time?]

ttt/player.py

@@ -1,4 +1,5 @@
 from click import Choice, prompt
+from strategy.lookahead_strategy import LookaheadStrategy
 from strategy.random_strategy import RandomStrategy
 from ttt.game import TTTGame
 import random
@@ -24,7 +25,7 @@ class TTTComputerPlayer:
     def __init__(self, name):
         "Sets up the player."
         self.name = name
-        self.strategy = RandomStrategy(TTTGame())
+        self.strategy = LookaheadStrategy(TTTGame(),deterministic=False)
 
     def choose_action(self, state):
         "Chooses a random move from the moves available."