added tests for Rp model's sklearn wrapper
added tests for Rp model's sklearn wrapper

ELind77/gensim,markroxor/gensim,RaRe-Technologies/gensim,summanlp/gensim,mattilyra/gensim,RaRe-Technologies/gensim,gojomo/gensim,macks22/gensim,gojomo/gensim,piskvorky/gensim,summanlp/gensim,ELind77/gensim,markroxor/gensim,piskvorky/gensim,gojomo/gensim,mattilyra/gensim,RaRe-Technologies/gensim,macks22/gensim,gojomo/gensim,piskvorky/gensim,ELind77/gensim,RaRe-Technologies/gensim,mattilyra/gensim,macks22/gensim,markroxor/gensim,summanlp/gensim