Feature Request - envlist select single latest environment

[Hecatron]

One of the use cases I tend to use tox for is a very simple cross platform way (windows linux) of creating a virtual environment for things like running mkdocs or other python uses.

I realise of course that virtualenv can be used for this, but the advantage here is that everything can just be put into a tox.ini config file and I can just specify a requirements.txt file and have everything needed installed at the same time and setup with a simple "tox" command, which makes things very easy for setup.

Would it be possible for envlist to have an option where we just select a single latest environment detected on the host such as envlist = LATEST The idea is then you can use tox to setup a single virtual env using the users latest installed version of python without specifically specifying what it is.

Alternative Solutions

Alternative solutions would probably involve creating some complicated bash or powershell scripts to get the first environment found then pass it in via -e perhaps. I also considered calling virtualenv from it's python cli but it's publicly accessible api's are a bit limited I think in so far as entering into that environment then installing stuff via pip