Mandelbrot demo requires Zarr-Python update

[d33bs]

Hello, thanks for the great work on this project! I noticed that there's an error with the 5th cell on the demonstration Google Colab notebook linked here: https://colab.research.google.com/github/hms-dbmi/vizarr/blob/main/python/notebooks/mandelbrot.ipynb . This happened when I tried a "run all cells" on the notebook.

The error states:

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
[<ipython-input-3-eee44cbf5fed>](https://localhost:8080/#) in <cell line: 0>()
     57 
     58 
---> 59 class MandlebrotStore(zarr.storage.BaseStore):
     60 
     61     def __init__(self, levels, tilesize, maxiter=255, compressor=None):

AttributeError: module 'zarr.storage' has no attribute 'BaseStore'

I imagine but don't know whether the Zarr API might have changed since the time the notebook was written.

[manzt]

Hi there, the Mandelbrot notebook requires Zarr-Python <3 (pip install "zarr<3"). I haven't had time to migrate to the latest release to accommodate the new APIs. However, the required changes should be to just the notebook (ie the use of zarr module to define a custom store) and not vizarr itself since vizare supports both the v2 and v3 zarr format.

[d33bs]

Thanks @manzt - I'll give that a try!

[manzt]

...and i'll try to migrate the example to zarr-python v3!