Placing a bet equaling the current highest bet.
Placing a bet equal to the highest bet, then adding more to become the highest
This allows the player to stay in the game without calling or raising, however,
this may only be done if no one has placed a bet before you.
By folding, you have forfeited any bets and any chance to win. You may do this
because you are out of money, or you do not think you can win. You also forfeit
the ability to see the winners cards if the winner won by everyone folding.