NOTE: We decided to follow the rules from wikipedia: https://en.wikipedia.org/wiki/Reversi

List of requirements for the command-line application:
- Flipping the counters: after each accepted move, the conters must be flipped.
- Turns must be switched between black and and white after each move
- Notify the user for illegal move, and reject it
- The game must be started by placing counters on the 4 squares at the middle of the board
	* The historical version of Reversi starts with an empty board, and the first two moves 
	made by each player are in the four central squares of the board. The players place their 
	disks alternately with their colors facing up and no captures are made. 
- Recognizing when the game is over
- Who won (based on the number of counters on the board)