Add option to ignore import errors in doctests
Add option to ignore import errors in doctests

--HG--
branch : ignore-doctest-import-errors

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