As a person who have taken a programming class and cried myself to sleep cuz i failed EVERY SINGLE SHIT IN IT, but managed to learn from youtube (fuck college) i can tell you that any programmer would Raise his/her hand in defeat if you asked them to program a jungler.
An AI won't know how to gank, clear, counter jungle or do anything. These decisions are ( at the moment ) Impossible to program. These things need a quick decision. It is hard to program quick decisions based on what is going on in the entire rift in order to tell the AI Whether it should clear another camp or help someone on their team.
It might be possible to teach an AI how to kite camps and clear one of them, but the problem is HOW to teach a clear path in the jungle to an AI ( a plan on what camps should i take now and thing i need to do based on my predictions on what will happen in the near future of the game.)
Don't forget that even if we solved everything i have said above, we still need to teach an AI how to get/def/steal dragons and barons.
[[[[ i dont play jungle so i have no idea if i am using wrong tearms]]]]]