Check the priority of open_store arguments vs schema vs environment.

[Paulie14]

According to zarr_fuse/zarr_storage.py:_zarr_fuse_options it seems that the order is following

1. use kwargs
2. use schema attrs
3. use environment

So (1) is the lowest priority.

Is this the intended behavior?

My counter example with opposite priorities:

1. I set up environment,
2. then I have several schemas (so I want to possibly overwrite the environment)
3. and finally I want to use one of the schema with different parameters (e.g. STORE_URL), so I want to overwrite it with kwargs..