test_from_file_invalid_config()

test_from_file_with_llm()

And some improvements where we make sure that temp files are definitely deleted after use.

Using index.describe instead of shape[].

The RouteLayer.categories() attribute has been removed, removing parts that reference this attribute form the tests.

RouteLayer.remove() renamed to delete().

installed poetry and ran make.  added mistralai to the pyproject.toml (first time using poetry, nice tool)

new encoder and a new LLMS. The encoder is a
simple wrapper around the MistralAI API, and the
LLMS is a simple wrapper around the encoder.
The encoder is tested with a simple unit test,
and the LLMS is tested with a simple unit test.

We don't have this function anymore.

And more linting.

Changes to the code meant we needed to change some pytests.

New pytests added for Conversation splitter method.

Also fixed a bug in cumulative_sim.py where we weren't limiting curr_split_docs to only latter docs after a split.