input: Write a python function to determine the winner of a Rock-Paper-Scissors game.
  assert find_winner('rock', 'rock') == 'draw'
  assert find_winner('rock', 'scissors') == 'player'
  assert find_winner('paper', 'rock') == 'player'
  assert find_winner('scissors', 'paper') == 'player'
  assert find_winner('scissors', 'rock') == 'computer'
output: def find_winner(player, computer):
      if player == computer:
          return 'draw'
      elif (player == 'rock' and computer == 'scissors') or \
           (player == 'paper' and computer == 'rock') or \
           (player == 'scissors' and computer == 'paper'):
          return 'player'
      else:
          return 'computer'