Connect 4!
Connect 4 is a game played on a grid with 7 columns and 6 rows. Players take it in turns to drop a symbol into a column – i.e. players choose a column between 1-7. The symbol will drop to the lowest empty row. The game is won if a player connects 4 of their symbols in a row, either horizontally, vertically or diagonally.
Your program should allow 2 players to take alternate turns to drop their symbols. After each turn the state of the board should be displayed so the next player can choose their column. Your program should announce the winner if a player manages to get 4 in a row!