function generateOnePlay() {
  const player1Hand = randomHand();
  const player2Hand = randomHand();
  const player1Win = compareHands(player1Hand, player2Hand);
  GAME_STATE.num_simulations_so_far++;
  return {player1Hand, player2Hand, player1Win};
}
Returns an object representing one complete play of the game.
Generates two random hands, and the value of the hand comparison.
Returns [hand1, hand2, whetherHand1Wins.