update changelog to 3.0.1
update changelog to 3.0.1

gojomo/gensim,RaRe-Technologies/gensim,piskvorky/gensim,mattilyra/gensim,piskvorky/gensim,gojomo/gensim,gojomo/gensim,RaRe-Technologies/gensim,RaRe-Technologies/gensim,RaRe-Technologies/gensim,mattilyra/gensim,markroxor/gensim,piskvorky/gensim,markroxor/gensim,markroxor/gensim,gojomo/gensim,mattilyra/gensim