input: Write a python function to simulate a "rock, paper, scissors" game and determine the winner.
  assert play_game("rock", "scissors") == "Player wins!"
  assert play_game("paper", "rock") == "Player wins!"
  assert play_game("scissors", "paper") == "Player wins!"
  assert play_game("rock", "rock") == "It's a tie!"
  assert play_game("scissors", "rock") == "Computer wins!"
output: def play_game(player_choice, computer_choice):
      if player_choice == computer_choice:
          return "It's a tie!"
      
      if (player_choice == "rock" and computer_choice == "scissors") or \
         (player_choice == "paper" and computer_choice == "rock") or \
         (player_choice == "scissors" and computer_choice == "paper"):
          return "Player wins!"
      
      return "Computer wins!"