BUG: Fix None comparison giving FutureWarning in choice function.
BUG: Fix None comparison giving FutureWarning in choice function.

This is in numpy/random/mtrand/mtrand.pyx where the choice function
was using comparisons of the form `None != p`.

chatcannon/numpy,nguyentu1602/numpy,MSeifert04/numpy,ekalosak/numpy,hainm/numpy,jankoslavic/numpy,bertrand-l/numpy,gmcastil/numpy,ekalosak/numpy,jakirkham/numpy,kirillzhuravlev/numpy,empeeu/numpy,GaZ3ll3/numpy,stuarteberg/numpy,ChanderG/numpy,gmcastil/numpy,groutr/numpy,GrimDerp/numpy,ContinuumIO/numpy,ContinuumIO/numpy,cjermain/numpy,pizzathief/numpy,cowlicks/numpy,rajathkumarmp/numpy,jschueller/numpy,githubmlai/numpy,dato-code/numpy,Eric89GXL/numpy,njase/numpy,rgommers/numpy,b-carter/numpy,tacaswell/numpy,rhythmsosad/numpy,NextThought/pypy-numpy,BabeNovelty/numpy,NextThought/pypy-numpy,cjermain/numpy,sonnyhu/numpy,dch312/numpy,chiffa/numpy,simongibbons/numpy,dato-code/numpy,skymanaditya1/numpy,shoyer/numpy,numpy/numpy,seberg/numpy,AustereCuriosity/numpy,yiakwy/numpy,ChristopherHogan/numpy,MaPePeR/numpy,hainm/numpy,shoyer/numpy,drasmuss/numpy,Linkid/numpy,Anwesh43/numpy,ViralLeadership/numpy,larsmans/numpy,madphysicist/numpy,ChanderG/numpy,grlee77/numpy,bringingheavendown/numpy,tacaswell/numpy,Eric89GXL/numpy,brandon-rhodes/numpy,ChanderG/numpy,joferkington/numpy,charris/numpy,KaelChen/numpy,Linkid/numpy,numpy/numpy,MichaelAquilina/numpy,chiffa/numpy,Linkid/numpy,Dapid/numpy,CMartelLML/numpy,sigma-random/numpy,BMJHayward/numpy,yiakwy/numpy,mathdd/numpy,solarjoe/numpy,Yusa95/numpy,skymanaditya1/numpy,pdebuyl/numpy,jakirkham/numpy,drasmuss/numpy,pdebuyl/numpy,rherault-insa/numpy,GrimDerp/numpy,brandon-rhodes/numpy,ESSS/numpy,seberg/numpy,rajathkumarmp/numpy,BMJHayward/numpy,jorisvandenbossche/numpy,MichaelAquilina/numpy,bmorris3/numpy,KaelChen/numpy,sonnyhu/numpy,sinhrks/numpy,grlee77/numpy,has2k1/numpy,Anwesh43/numpy,brandon-rhodes/numpy,ahaldane/numpy,ESSS/numpy,gfyoung/numpy,sonnyhu/numpy,charris/numpy,mortada/numpy,njase/numpy,mingwpy/numpy,anntzer/numpy,mattip/numpy,andsor/numpy,ajdawson/numpy,tdsmith/numpy,ekalosak/numpy,KaelChen/numpy,rgommers/numpy,WarrenWeckesser/numpy,dimasad/numpy,jankoslavic/numpy,jonathanunderwood/numpy,tdsmith/numpy,SunghanKim/numpy,rmcgibbo/numpy,drasmuss/numpy,MSeifert04/numpy,rudimeier/numpy,mortada/numpy,skwbc/numpy,mhvk/numpy,mhvk/numpy,chiffa/numpy,nguyentu1602/numpy,githubmlai/numpy,endolith/numpy,ssanderson/numpy,Dapid/numpy,abalkin/numpy,felipebetancur/numpy,felipebetancur/numpy,jonathanunderwood/numpy,charris/numpy,kirillzhuravlev/numpy,rhythmsosad/numpy,b-carter/numpy,bringingheavendown/numpy,yiakwy/numpy,groutr/numpy,rudimeier/numpy,tacaswell/numpy,felipebetancur/numpy,empeeu/numpy,ddasilva/numpy,njase/numpy,shoyer/numpy,githubmlai/numpy,Yusa95/numpy,chatcannon/numpy,jankoslavic/numpy,sinhrks/numpy,MichaelAquilina/numpy,bertrand-l/numpy,NextThought/pypy-numpy,mwiebe/numpy,argriffing/numpy,dwillmer/numpy,rmcgibbo/numpy,mwiebe/numpy,dimasad/numpy,cowlicks/numpy,ChanderG/numpy,skwbc/numpy,GaZ3ll3/numpy,tynn/numpy,Yusa95/numpy,joferkington/numpy,ContinuumIO/numpy,musically-ut/numpy,utke1/numpy,jankoslavic/numpy,Eric89GXL/numpy,rgommers/numpy,nguyentu1602/numpy,has2k1/numpy,BabeNovelty/numpy,jorisvandenbossche/numpy,ESSS/numpy,mathdd/numpy,empeeu/numpy,rudimeier/numpy,sigma-random/numpy,numpy/numpy,ahaldane/numpy,solarjoe/numpy,SunghanKim/numpy,pdebuyl/numpy,mhvk/numpy,CMartelLML/numpy,GrimDerp/numpy,BabeNovelty/numpy,dwillmer/numpy,pyparallel/numpy,mathdd/numpy,pyparallel/numpy,CMartelLML/numpy,WarrenWeckesser/numpy,seberg/numpy,rhythmsosad/numpy,Srisai85/numpy,b-carter/numpy,musically-ut/numpy,rherault-insa/numpy,seberg/numpy,ahaldane/numpy,mindw/numpy,jorisvandenbossche/numpy,githubmlai/numpy,mattip/numpy,cjermain/numpy,behzadnouri/numpy,cjermain/numpy,pbrod/numpy,ajdawson/numpy,charris/numpy,AustereCuriosity/numpy,behzadnouri/numpy,gfyoung/numpy,kiwifb/numpy,WarrenWeckesser/numpy,Srisai85/numpy,behzadnouri/numpy,naritta/numpy,jorisvandenbossche/numpy,stuarteberg/numpy,MichaelAquilina/numpy,trankmichael/numpy,tdsmith/numpy,empeeu/numpy,pbrod/numpy,grlee77/numpy,sigma-random/numpy,jorisvandenbossche/numpy,KaelChen/numpy,bmorris3/numpy,pbrod/numpy,ddasilva/numpy,kiwifb/numpy,rajathkumarmp/numpy,tynn/numpy,madphysicist/numpy,WarrenWeckesser/numpy,utke1/numpy,bmorris3/numpy,jonathanunderwood/numpy,WillieMaddox/numpy,mingwpy/numpy,ChristopherHogan/numpy,kirillzhuravlev/numpy,grlee77/numpy,GaZ3ll3/numpy,pbrod/numpy,andsor/numpy,SiccarPoint/numpy,GaZ3ll3/numpy,tdsmith/numpy,jakirkham/numpy,musically-ut/numpy,skwbc/numpy,abalkin/numpy,Linkid/numpy,ssanderson/numpy,chatcannon/numpy,sinhrks/numpy,ChristopherHogan/numpy,MSeifert04/numpy,felipebetancur/numpy,rhythmsosad/numpy,grlee77/numpy,pizzathief/numpy,kiwifb/numpy,sigma-random/numpy,maniteja123/numpy,nguyentu1602/numpy,mindw/numpy,MSeifert04/numpy,larsmans/numpy,shoyer/numpy,joferkington/numpy,utke1/numpy,pyparallel/numpy,Anwesh43/numpy,dimasad/numpy,leifdenby/numpy,nbeaver/numpy,moreati/numpy,BabeNovelty/numpy,moreati/numpy,jakirkham/numpy,musically-ut/numpy,MSeifert04/numpy,dato-code/numpy,BMJHayward/numpy,argriffing/numpy,mortada/numpy,cowlicks/numpy,yiakwy/numpy,maniteja123/numpy,rherault-insa/numpy,hainm/numpy,SunghanKim/numpy,sinhrks/numpy,ajdawson/numpy,kirillzhuravlev/numpy,jakirkham/numpy,SiccarPoint/numpy,mingwpy/numpy,gfyoung/numpy,sonnyhu/numpy,leifdenby/numpy,ekalosak/numpy,madphysicist/numpy,dwillmer/numpy,trankmichael/numpy,bertrand-l/numpy,stuarteberg/numpy,ahaldane/numpy,bringingheavendown/numpy,anntzer/numpy,abalkin/numpy,gmcastil/numpy,jschueller/numpy,ViralLeadership/numpy,mwiebe/numpy,ajdawson/numpy,numpy/numpy,has2k1/numpy,pizzathief/numpy,Eric89GXL/numpy,MaPePeR/numpy,simongibbons/numpy,mathdd/numpy,Srisai85/numpy,naritta/numpy,dch312/numpy,dimasad/numpy,mattip/numpy,WillieMaddox/numpy,SunghanKim/numpy,SiccarPoint/numpy,bmorris3/numpy,MaPePeR/numpy,anntzer/numpy,trankmichael/numpy,ssanderson/numpy,dwillmer/numpy,naritta/numpy,skymanaditya1/numpy,dch312/numpy,rudimeier/numpy,endolith/numpy,Anwesh43/numpy,dato-code/numpy,shoyer/numpy,madphysicist/numpy,brandon-rhodes/numpy,hainm/numpy,endolith/numpy,groutr/numpy,larsmans/numpy,naritta/numpy,mindw/numpy,BMJHayward/numpy,stuarteberg/numpy,jschueller/numpy,solarjoe/numpy,Dapid/numpy,ChristopherHogan/numpy,mattip/numpy,madphysicist/numpy,ahaldane/numpy,anntzer/numpy,tynn/numpy,mingwpy/numpy,endolith/numpy,WillieMaddox/numpy,andsor/numpy,moreati/numpy,AustereCuriosity/numpy,SiccarPoint/numpy,maniteja123/numpy,rajathkumarmp/numpy,GrimDerp/numpy,WarrenWeckesser/numpy,ViralLeadership/numpy,skymanaditya1/numpy,rmcgibbo/numpy,jschueller/numpy,pizzathief/numpy,nbeaver/numpy,CMartelLML/numpy,argriffing/numpy,larsmans/numpy,ddasilva/numpy,simongibbons/numpy,MaPePeR/numpy,NextThought/pypy-numpy,cowlicks/numpy,rgommers/numpy,pbrod/numpy,mindw/numpy,rmcgibbo/numpy,mhvk/numpy,trankmichael/numpy,pizzathief/numpy,simongibbons/numpy,Yusa95/numpy,mortada/numpy,mhvk/numpy,has2k1/numpy,nbeaver/numpy,joferkington/numpy,andsor/numpy,dch312/numpy,Srisai85/numpy,leifdenby/numpy,pdebuyl/numpy,simongibbons/numpy