To run the code, run the main method class.
When the main method is run, the board GUI will appear, and the user can click on any column to play the first piece (which will be red). Clicking any other column will then play the next piece, then so on. When any player makes four pieces in a row, text will come up displaying the winner. The user can then click on any column to start the next game and reset the board. If there is a tie (whole board filled without a winner) then the user can click the board again to reset the board.