Explore removing the need for Geofrabrik/BBBike

[rgreinho]

Feature request

Current Behavior

Currently, we retrieve the osm.pbf files from either Geofrabrik, either BBBike. This works fine, but is not always optimal. For instance, when analyzing a Spanish city, we retrieve the data of the full country instead of the specific area since PyrOSM does not yet handle the communities (work in progress: pyrosm/pyrosm#203).

Expected Behavior

We should download the more specific areas all the time. This would speed up the "prepare" part of the process.

Possible Solution

A solution would be to leverage OSMNX to download the specific area in .osm, and then convert it to .osm.pbf with osmium.