Convert Vegvesen NVDB road networks to OpenDRIVE files

1. Install requirements: pip install -r requirements.txt
2. Make a new configuration of the area you want to convert in run_tools.py and make sure run_download_data() is run in __main__
3. Run the download script: run_tools.py
4. Make a new configuration in nvdb_to_opendrive.py using the same JSON file
5. Run it: python nvdb_to_opendrive.py

• Handle changing number of lanes properly
• Infer turn restrictions
• Incorporate optional road polygon data
• Expand to OSM dataset
• Lane access for bus lanes
• Setting types for exit ramps
• Fix roundabouts and missing roads
• Junctions