Add `download-examples` CLI command to setup.py for getting all notebook

[brendancol]

We want to be able to do this:

$> xrspatial download-examples

Exactly like datashader

• [x] Pharmacy Deserts ( https://github.com/makepath/xarray-spatial/blob/master/examples/pharmacy-deserts.ipynb)
• [x] Store example datasets in Public / Anonymous Read Azure Bucket

[jbednar]

Note that Datashader and other HoloViz projects provide copy_examples (copy the examples from where they are stashed in the python directory into the user's cwd), fetch_data (which typically downloads the data), and examples (which invokes both copy_examples and fetch_data). So if you want it to be comparable to how Datashader does it (so that you can easily give users instructions for both), what you're discussing here appears to be fetch_data, not being about examples (which for Datashader are notebooks, not datasets).

[calexat-123]

Done, but with notes for additional work needed. 'copy-examples', 'fetch-data', and 'examples' commands work. It is not attached to an azure bucket yet, because I still need access to that, as well as to the pharmacy location data source, but I tested it with a sample dataset from Kaggle and an aws bucket.

[giancastro]

@lex-c, has this issue already solved?