Fix scroll direction as UP was going down (and DOWN up).

[lgringo]

When FxRobot has been refactored, Up and Down scroll have been inverted.

Old code :

/**
 * Scrolls the mouse-wheel a given number of notches in a direction.
 *
 * @param amount    the number of notches to scroll
 * @param direction
 * @return
*/
public GuiTest scroll(int amount, VerticalDirection direction) {
    for (int x = 0; x < Math.abs(amount); x++) {
       screenRobot.scrollMouse(directionToInteger(direction));
    }
    return this;
 }

private int directionToInteger(VerticalDirection direction) {
    if (direction == VerticalDirection.UP)
        return -1;
     return 1;
 }

Actual code is :

@Override
public void scroll(int amount) {
    if (amount >= 0) {
        scrollUp(amount);
    }
    else {
        scrollDown(Math.abs(amount));
    }
}
[...]
@Override
public void scrollUp(int positiveAmount) {
    for (int scrollTick = 0; scrollTick < positiveAmount; scrollTick++) {
        screenRobot.scrollMouse(1);
    }
}

@Override
public void scrollDown(int positiveAmount) {
    for (int scrollTick = 0; scrollTick < positiveAmount; scrollTick++) {
        screenRobot.scrollMouse(-1);
    }
}

Regression test added (I hope the Duke with a guitar image do not have a copyright).

[hastebrot]

Thanks!