option to pass args to conda

[majidaldo]

devenv can simply be for env vars while conda takes care of the rest. default passed arg would be --prune.

(maybe this will help with mamba integration if the conda folks do it...i expect this is the best path)

[prusse-martin]

We under the hood already just merge conda dependencies (creating a plain enviroment.yml) and foward the call to conda to solve the dependencies and create the enviroment. after that is completed we add thge scripts to set the env vars in the enviroment.

[prusse-martin]

There is #110 to add mamba support, but that is inactive for some time now.

[prusse-martin]

Sorry, and about allow to pass arbitrary args to conda I aggree.