Add pipeline for tests

[thejaminator]

Added a CI pipeline to run tests. Should catch errors like this as well. https://github.com/openai/openai-python/issues/199

Example on my fork here https://github.com/thejaminator/openai-python/pull/1

The maintainers of this repo will need to set an environment API key OPENAI_API_KEY=<API-KEY> as a github secret, so the tests that require an API key will be run as part of the pipeline.

Alternatively, tests that require authentication with the API key can be separated from those that don't. And we can disable those that require authentication. Or mock the API response.

[thejaminator]

@hallacy @ddeville would this MR be helpful?

[rattrayalex]

Thanks for this!

We've since rewritten the library entirely, so this change is no longer relevant. I'm sorry we didn't get to it sooner.

We currently run CI for this repo in a private mirror, but hope to add public CI with tests soon.