Add cenpy & osmnx example notebook

[ljwolf]

This adds an example with using contextily to add tiles to an osmnx and cenpy-generated map of Austin, TX.

It also has black ran on the docs/conf.py file.

[darribas]

Super, my only comment would be to change the main title of the notebook to something like "cenpy & osmnx and then adding the current title as a subtitle (on GEE I've used four #). That way the title pulled in for the menu bar is shorter and easier to render. Otherwise good to go!

[ljwolf]

Thanks! I've shortened the main title an added a clearer/more descriptive subtitle as an h4.

[jorisvandenbossche]

One small comment might also be that the section explaining what contextily is, might be unneeded for a notebook in the contextily docs ;)

[ljwolf]

sure sure, I only put that in to ensure that if it is linked to without context, it's got at least some explanation. Happy to drop that!

[darribas]

I think this is cool as is. One suggestion to extend it (maybe add below rather than edit the map that's there) could be:

• Use a dark basemap (Carto's dark matter?)
• "Transfer" the values from the Census geographies to the street network
• Make a choropleth of the street network on top of contextily

If you like this, wanna have a go at this and think will have time soon, I'd say go ahead and we merge everything at once. But it you don't see yourself with bandwith with this any time soon, I'd say let's merge this and "if it happens" in the future, we can always extend the notebook, that's not a problem.

[darribas]

Merging this and we can pick up that to-do list above in a different PR

[darribas]

Merging as failed tests aren't related to this PR