Add this test

Hi there,

I've just finish the bacteria colonies task by using simple heuristics. My solution passes all the tests but there is some cases where those heuristics are not working (see the attached picture). Therefore it would be nice to add this test:

healthy(((0,0,0,0,0,1,0,0,0,0,1,1,0,0,0),(0,0,0,0,1,1,1,0,0,0,1,1,1,0,0),(0,0,0,0,0,1,0,0,0,1,1,1,1,1,0),(0,0,0,0,0,0,0,0,1,1,1,1,1,1,1),(0,0,0,1,0,0,0,0,0,1,1,1,1,1,0),(0,0,1,1,1,0,0,0,0,0,1,1,1,0,0),(0,1,1,1,1,1,0,0,0,0,0,1,0,0,0),(1,1,1,1,1,1,1,0,0,0,0,0,0,0,0),(0,1,1,0,1,1,0,0,0,0,1,0,0,0,0),(0,0,1,1,1,1,0,0,0,1,1,1,0,0,0),(0,0,0,1,0,0,0,0,1,1,1,1,1,0,0),(0,0,0,0,0,0,0,1,1,1,1,1,1,1,0),(0,0,0,0,0,0,0,0,1,1,1,1,1,0,0),(0,0,0,0,0,0,0,0,0,1,1,1,0,0,0),(0,0,0,0,0,0,0,0,0,0,0,0,0,0,0)))