Add a simple test suite for doing downstream tests

[mariusvniekerk]

No description provided.

[martindurant]

Does this need to be merged before the first tests would run?

[mariusvniekerk]

Yep it does

[martindurant]

Can we please do this in two stages, one to add the CI, and then another to add the tests?

[jorisvandenbossche]

@mariusvniekerk do the tests actually pass at the moment?

[mariusvniekerk]

Rebased to put it into the ci.yml to see if they would trigger.

[mariusvniekerk]

They don't :(

[martindurant]

The run is here: https://github.com/mariusvniekerk/s3fs/actions/runs/410872762

but apparently there is a syntax problem

[mariusvniekerk]

There we go

[martindurant]

That's a lot of "❌"!

[mariusvniekerk]

How big do we want the test matrix to be?

[martindurant]

Er, it does seem like a lot. It would be enough to be python versions on linux and one version for win. I wouldn't even bother with osx...

Note that fsspec runs the s3fs test suite on all CI runs, and dask does indeed have a couple of s3 tests.