[UNTESTED][BIG ERROR] Goal PID Direction

The y-axis for AT tracking is pointing upward in contrary to the ball seeking. Ball seeking which uses pixel. If the position of the blimp is higher than the green ball the error will be positive as the ball will be at a lower pixel (higher numerical pixel value). On the other hand, if we have an AT instead of a green ball, the error will be negative as the AT is in a lower position in meter. Thus, the vertical direction syntax of the PID control needs to be opposite