Add badge of supported python versions to README
Add badge of supported python versions to README
alfredodeza/pytest,skylarjhdownes/pytest,The-Compiler/pytest,etataurov/pytest,tomviner/pytest,eli-b/pytest,vmalloc/dessert,lukas-bednar/pytest,MengJueM/pytest,txomon/pytest,ropez/pytest,MichaelAquilina/pytest,pytest-dev/pytest,flub/pytest,lukas-bednar/pytest,hpk42/pytest,vodik/pytest,Bachmann1234/pytest,nicoddemus/pytest,ddboline/pytest,hpk42/pytest,davidszotten/pytest,malinoff/pytest,omarkohl/pytest,ropez/pytest,JonathonSonesen/pytest,vodik/pytest,The-Compiler/pytest,tomviner/pytest,jaraco/pytest,nicoddemus/pytest,omarkohl/pytest,userzimmermann/pytest,markshao/pytest,userzimmermann/pytest,tareqalayan/pytest,JonathonSonesen/pytest,tgoodlet/pytest,Bachmann1234/pytest,rmfitzpatrick/pytest,MengJueM/pytest,Akasurde/pytest,hackebrot/pytest,RonnyPfannschmidt/pytest,pfctdayelise/pytest