Extending the robot task.
=========================

Change Example01 so that the robot marks out all four corners of a square.

How it's done:

First increase the robot's beeper count from three to four, so change the line

        Robot karel = new Robot(1, 2, East, 3);  

so that it reads

        Robot karel = new Robot(1, 2, East, 4);  

Second, make the robot move to and place the final corner of the sqaure.  Before the last

        karel.putBeeper();

insert these lines:

        karel.turnLeft(); 
        karel.putBeeper();
        karel.move();  
        karel.move();  
        karel.move(); 
