Osmnx

- add ability to save graph as geopackage file
- add truncate_by_edge implementation in truncate_graph_polygon
- allow flexible overpass settings (e.g., to query by date)
- better handling of invalid footprint geometries
- geocode function now uses nominatim_request function
- improve .osm xml output
- improve one-way street handling
- fix graph projection overwriting original lat/lng
- fix redistribute_vertices function for MultiLineStrings

- fix .osm xml output
- fix for pandas 1.0

- fix errant print statement

- fix .osm xml output
- fix geopandas future compatibility

- fix get_nearest_edges search when not using a spatial index

- drop formal python 2 support
- refactor all modules for cleaner package organization
- make stats betweenness centrality compatible with networkx>=2.4
- allow configurable overpass and nominatim endpoints
- allow gdf_from_places to take a which_result list argument
- handle zero-division in street grade calculation
- better footprint relation handling
- improve network type queries for better filtering
- fix pois_from_polygon returning points outside polygon