Osmnx

- add optional cleaned intersections count to basic stats
- allow circuity to be calculated for projected or unprojected networks
- various code clean-up and refactoring

- add requirements files to distribution

- add ability to download other infrastructures besides just roads/paths (e.g., rail lines, power lines, etc.)
- calculate graph edges' bearings
- add ability to get nearest node by great circle or euclidean distance
- move examples/demo notebooks to new repo: osmnx-examples
- fix docstrings
- fix building footprint downloads that require multiple calls for large areas
- fix missing MultiPolygon import in buildings module

- functionality to clean-up and consolidate complex intersections
- let save_gdf_shapefile save building footprint GeoDataFrames
- set node color correctly in figure-ground diagrams

- add elevation module to get node elevations and street grades
- new color sequence creation and conversion functions in plot module
- new function to get a path's edge attribute values
- gracefully handle subpolygons that are invalid or have zero area
- make truncate_graph_polygon work on projected graphs
- plot_shape accepts a color or a list of colors
- make all requests to Overpass API set custom user-agent and referer
- rewrite algorithms to convert multidigraphs to multigraphs

- fix load_graphml so we can save a graph again after loading it
- fix load_graphml so edge oneway attribute is not always set to True
- buildings module gets buildings stored in OSM as relations as well as ways
- fix figure-ground diagram saving to make perfect square and smooth joints
- add optional graph argument to plot_figure_ground
- suppress jupyter notebook deprecation warnings