pivot() controls the pivot speed of the RedBot. The values of the pivot function inputs
            range from -255:255, with -255 indicating a full speed counter-clockwise rotation.
            255 indicates a full speed clockwise rotation

def pivot(self, speed, durationS=-1.0):
        """
            pivot() controls the pivot speed of the RedBot. The values of the pivot function inputs
            range from -255:255, with -255 indicating a full speed counter-clockwise rotation.
            255 indicates a full speed clockwise rotation
        """
        if speed < 0:
            self.left_fwd(min(abs(speed), 255))
            self.right_rev(min(abs(speed), 255))
        else:
            self.left_rev(min(abs(speed), 255))
            self.right_fwd(min(abs(speed), 255))
        if durationS > 0:
            self.board.sleep(durationS)
            self.left_stop()
            self.right_stop()