Use python 3 in 'doctesting' environment
Use python 3 in 'doctesting' environment

We some examples now use type annotations

tomviner/pytest,nicoddemus/pytest,RonnyPfannschmidt/pytest,hackebrot/pytest,pytest-dev/pytest,The-Compiler/pytest,nicoddemus/pytest,markshao/pytest,The-Compiler/pytest,alfredodeza/pytest,Akasurde/pytest,tomviner/pytest