New feature that would allow environments to be created with R or Lua instead of Python

[kesmit13]

Currently, tox and tox-conda assume that they are being used for building and testing Python environments. However, Anaconda also supports R and Lua environments. It would be nice if it was possible to create an environment for those languages instead of Python. Currently, you can still create test environments, but Python always comes along for the ride even if you don't want it (which can sometimes cause dependency issues).

I'm thinking that maybe a language_base= option could be added to the top-level config that gives the base specification; something like python=3.8, r-base=3.4.3, mro-base=3.5.1, etc. That would be used for the initial environment creation rather than always just installing python.

There could be other niceties add too such as cran_deps= or lua_deps= to install from CRAN and LuaRocks repos, but I'd be happy with just being able to create environments for those other languages for now.

[kesmit13]

Actually, for my current use case, I really just need to specify something like language_base = none so that it creates an empty environment. Then conda_deps= can specify the language base to install.

[gaborbernat]

Currently, tox and tox-conda assume that they are being used for building and testing Python environments.

There's a tox rewrite on-going under https://github.com/tox-dev/tox/tree/rewrite#rewrite-branch, which removes this assumption.