Add "environmentPath" init option, for Jedi "environment_path"

[gwerbin]

This PR is intended to address the feature request in #199.

I'm not sure how to formally test this, but I have confirmed that it works as follows.

First, set up two venvs: one with this branch pip install-ed, and another with a nontrivial library dependency:

git clone https://gwerbin/jedi-language-server gwerbin_jedi-language-server
cd gwerbin_jedi-language-server

python -m venv ./jedi-env
./jedi-env/bin/pip install -e .

python -m venv ./work-env
./work-env/bin/pip install -U numpy

Then configure the following in Neovim LSP Config:

    lspconfig.jedi_language_server.setup({
      cmd = { '/path/to/jedi-env/bin/jedi-language-server' },
      on_new_config = function(new_config, root_dir)
        new_config.init_options = {
          workspace = {
            environmentPath = '/path/to/work-env/bin/python',
          },
        }
      end,
    }))

Finally, use Neovim to create a new Python file called nptest.py. You should be able to write import numpy as np at the top of the file and see Jedi completions for Numpy with np.<tab>, e.g. np.random.default_rng().

Confirm also that if you remove cmd = from the Neovim config above, that Numpy library completion no longer works when editing nptest.py.

[pappasam]

Thanks for the PR! To speed things up, I suggest running the tests locally and resolving any errors. make test will be helpful!

[gwerbin]

Thanks for merging this!

I'm relieved that it was such a quick fix. I strongly prefer Jedi LS compared to both PyLSP and the newcomer Anakin (although I figured out how to do it by reading the Anakin docs).

Now that this feature is merged, I'm eager to start using Jedi LS again.

Do you have a rough estimate for when this will land in PyPI? Wow, that was quick! https://pypi.org/project/jedi-language-server/0.38.0/