To do: handle relative paths or directory-specific kernels

[mcg1969]

Suppose conda's envs_dirs configuration includes a relative path among its entries (whether in the .condarc, in an environment variable, or anywhere else it can be configured). This means that conda's environment search depends on the directory you are currently in.

This actually has some genuinely good uses. For instance, suppose you add ./envs to your envs_dirs path. Then you now have a simple mechanism for finding project-specific environments. Just create a subdirectory named envs in your environment, then do conda create -p envs/<name> ..., and conda will automatically start picking it up when you are in that directory.

It would be great of nb_conda_kernels could handle this elegantly. To do so, it would need to be notified whenever the user moves into a new directory in the Jupyter file browser, and rescan the environment list.