Add devcontainer, update test_requirements.txt

[arogozhnikov]

Motivation: makes easier to contribute.

Currently to test things locally I need to delete aws config, and manually change requirements for tests, create virtual env and setup pre-commit

I can confirm that after spinning up the container, I can run pytest s3fs and it works:

========================================== 313 passed, 1 skipped, 3 xfailed, 12 warnings in 150.68s (0:02:30) ==========================================

[martindurant]

How is this executed? Is this docker? I would say that requiring docker is actually more onerous. Simpler would be a pytest fixture that masks any environment variables that were creating trouble for you.

[arogozhnikov]

docker or podman-as-docker if you run it on your machine.

For me that's this button:

[arogozhnikov]

For local development, pycharm and vs code support devcontainers now and start/manage container for you.

[arogozhnikov]

For me that's this button:

you need devcontainer.json first to make button work correctly.

[martindurant]

So you still need docker, and also one of the particular IDEs that supports this mechanism. I am mildly against the idea.

[arogozhnikov]

up to you of course.

I'd spend 10 minutes setting this up rather ~3 hours figuring out why tests didn't work on mac or on linux, but worked in CI