* Note: please do not check-in your .class files in the future.
   * Note: don't delete README.md file in the future. I'll be using it to record your grade and provide my comments. 
   * Note: in Game::start() function, if you adjust currentPlayerIndex as the first thing in the loop, you will not need to correct it later in your code (to announce the correct winner)
   * Note: when range checking values, [Example: if ((x < 3 && x >= 0)], it is best to go from smallest to largerst values, as in if (x >=0 && x < 3). This makes your code easier to read
   * Note: when using a function that returns a boolean in an if-statment [ Example if (board.hasWinner() == true)], it is redundant to compare it to a boolean constatnt true/false. I would rewirte it as: if (board.hasWinner() ).
   * Note: you should print the board between players' turns, otherwise, it's pretty hard to play the game (2)
   * Note: Game::start() - you can use board.hasOpenePositions() to determine if the playing loop should continue (instead of a for loop that loops at most 9 times). This will generalize better, if we were to switch the board to have different dimensions.
   * Note: Bracket and code alignment issues. Do not use tabs.