Feature ray

[bradday4]

This PR address issue #26 .

Things to note.

• I've updated the tests.yml to install ray in a local environment for testing. Also created a new pytest.ini file for ignoring deprecation warnings that ray throws. This is an issue that the maintainers of joblib will deal with so I don't see any reason to clutter pytest responses with a 100+ deprecation warnings.

• Also made some minor modifications to the Runner docstring to reflect support for ray. I've performed the unit tests locally any everything checks out.

• Code coverage has one caveat being the try - except block in Runner._run which catches the import error for ray. If we really wanted to run this bit of code we would need to alter tests.yml to run a specific test without ray installed, then install ray and run the normal test suite. I figured this was too much work for 5 lines of coverage.

• other odds and ends.

Let me know if you need me to do anything else.

[bradday4]

Mainly have a question on weather or not ray needs to be running as a service beforehand or if we can start ray just for our own run.

Ray does not need to be running as a service. I.e called explicitly from the CLI before hand. We can use ray.init() in the code itself to start the server locally. I guess it would make things easier from a CI perspective since its one less build step during testing.