lookahead keep tail
addresses https://github.com/twanvl/snake/issues/2
running snake.exe all on master is broken and it seems to be due to using Lookahead::many_move_tail for cell tree algo by default instead of Lookahead::many_keep_tail
using the later fixes snake.exe all and reproduces results consistent with the README.
this fixes it, I wonder why it was changed.
I am still trying to translate the code over to python and seem to run into issues but this is not the reason why I couldn't port it, Though I was kinda hoping changing over to using many_keep_tail in the python code would fix it.
closing because @twanvl makes a good point in this discussion: https://github.com/twanvl/snake/issues/2 Opening a separate PR with the better solution