[PSR] Update of assignment 4

[Jaroslav Klapálek]

Dear students,

   auto-evaluation for fourth assignment was updated. Now, your code
should be more likely to pass. Also, third test was marked as optional,
since its completion is highly dependent on choice of variables.

Do not forget that in order to be awarded with points, your solution has
to be demonstrated on the real hardware.


Sincerely

Jaroslav Klapálek