Use pip and tox from py27 in appveyor
Use pip and tox from py27 in appveyor

gabrielcnr/pytest,JonathonSonesen/pytest,vodik/pytest,markshao/pytest,alfredodeza/pytest,etataurov/pytest,pytest-dev/pytest,davidszotten/pytest,tomviner/pytest,tgoodlet/pytest,pfctdayelise/pytest,The-Compiler/pytest,oleg-alexandrov/pytest,hpk42/pytest,mhils/pytest,RonnyPfannschmidt/pytest,ropez/pytest,jaraco/pytest,icemac/pytest,bukzor/pytest,skylarjhdownes/pytest,chillbear/pytest,userzimmermann/pytest,lukas-bednar/pytest,mdboom/pytest,mhils/pytest,MengJueM/pytest,vodik/pytest,eli-b/pytest,jb098/pytest,Akasurde/pytest,malinoff/pytest,Bachmann1234/pytest,nicoddemus/pytest,ionelmc/pytest,oleg-alexandrov/pytest,mbirtwell/pytest,chiller/pytest,tomviner/pytest,lukas-bednar/pytest,mdboom/pytest,Bjwebb/pytest,JonathonSonesen/pytest,userzimmermann/pytest,gabrielcnr/pytest,The-Compiler/pytest,tareqalayan/pytest,Bjwebb/pytest,ionelmc/pytest,chiller/pytest,rouge8/pytest,Bachmann1234/pytest,icemac/pytest,hackebrot/pytest,rouge8/pytest,omarkohl/pytest,MengJueM/pytest,ropez/pytest,nicoddemus/pytest,MichaelAquilina/pytest,txomon/pytest,ddboline/pytest,chillbear/pytest,flub/pytest,vmalloc/dessert,hpk42/pytest,jb098/pytest,rmfitzpatrick/pytest,mbirtwell/pytest,omarkohl/pytest,bukzor/pytest