WikiExtractor command needs to be updated

[FremyCompany]

WikiExtractor command needs to be updated or the specific commit of WikiExtractor should be select such that it still works with the current command. I think the last compatible commit is git checkout 6408a430fc504a38b04d37ce5e7fc740191dee16.

[FremyCompany]

(I am trying to run the GPT2 fine tuning notebook, sorry, should have added that context in the first message; the command in question is in the nputils_fastai2 code; I would also note that it seems fastai2 is now named simply fastai, so the imports need to be updated as well)