minor: cleanup tox.ini
minor: cleanup tox.ini

pfctdayelise/pytest,ddboline/pytest,davidszotten/pytest,rmfitzpatrick/pytest,tomviner/pytest,pytest-dev/pytest,The-Compiler/pytest,tomviner/pytest,Akasurde/pytest,markshao/pytest,nicoddemus/pytest,alfredodeza/pytest,The-Compiler/pytest,txomon/pytest,tareqalayan/pytest,hackebrot/pytest,RonnyPfannschmidt/pytest,nicoddemus/pytest