README.rst: Add drone.io link and build badge image
README.rst: Add drone.io link and build badge image

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branch : add_drone_io_to_README_rst

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