Update for zarr 3.0.0 #49
Description
The migration guide still says it's a "work-in-progress":
https://zarr.readthedocs.io/en/stable/user-guide/v3_migration.html#work-in-progress
Several things will need to be updated including:
- KVStore, TempStore, DirectoryStore, NestedDirectoryStore no longer exists
- creation no longer exists
- the base class is zarr.abc.store.Store (instead of zarr.storage.Store)