Fix instructions for nose users.
Fix instructions for nose users.

--HG--
branch : fix-nose-docs

vodik/pytest,flub/pytest,vmalloc/dessert,rouge8/pytest,etataurov/pytest,nicoddemus/repo-test,bukzor/pytest,inirudebwoy/pytest,ropez/pytest,omarkohl/pytest,doordash/pytest,chillbear/pytest,The-Compiler/pytest,userzimmermann/pytest,mbirtwell/pytest,mbirtwell/pytest,codewarrior0/pytest,Akasurde/pytest,hackebrot/pytest,mhils/pytest,Carreau/pytest,bukzor/pytest,Bachmann1234/pytest,vodik/pytest,rmfitzpatrick/pytest,inirudebwoy/pytest,MengJueM/pytest,rouge8/pytest,icemac/pytest,oleg-alexandrov/pytest,omarkohl/pytest,bubenkoff/pytest,hunse/pytest,abusalimov/pytest,tomviner/pytest,icemac/pytest,lukas-bednar/pytest,ojake/pytest,alfredodeza/pytest,bubenkoff/pytest,takluyver/pytest,chiller/pytest,ericdill/pytest,JonathonSonesen/pytest,malinoff/pytest,Haibo-Wang-ORG/pytest,pelme/pytest,markshao/pytest,takluyver/pytest,tgoodlet/pytest,txomon/pytest,codewarrior0/pytest,ericdill/pytest,oleg-alexandrov/pytest,pytest-dev/pytest,skylarjhdownes/pytest,Haibo-Wang-ORG/pytest,The-Compiler/pytest,nicoddemus/pytest,Bachmann1234/pytest,hpk42/pytest,Bjwebb/pytest,ghostsquad/pytest,mdboom/pytest,jb098/pytest,jb098/pytest,nicoddemus/pytest,chillbear/pytest,untitaker/pytest,davidszotten/pytest,wfxiang08/pytest,Bjwebb/pytest,mdboom/pytest,tomviner/pytest,pelme/pytest,eli-b/pytest,MichaelAquilina/pytest,jaraco/pytest,JonathonSonesen/pytest,hpk42/pytest,abusalimov/pytest,ojake/pytest,Carreau/pytest,ionelmc/pytest,ddboline/pytest,pfctdayelise/pytest,mhils/pytest,gabrielcnr/pytest,hunse/pytest,ionelmc/pytest,chiller/pytest,gabrielcnr/pytest,lukas-bednar/pytest,wfxiang08/pytest,ghostsquad/pytest,ropez/pytest,doordash/pytest,nicoddemus/repo-test,tareqalayan/pytest,RonnyPfannschmidt/pytest,MengJueM/pytest,untitaker/pytest,userzimmermann/pytest