What problem in GTFS datasets does this new rule address? Please describe.
The GTFS specification mentions in stops.stop_name:

Conditionally Required:

• Required for locations which are stops (location_type=0), stations (location_type=1) or entrances/exits (location_type=2).
• Optional for locations which are generic nodes (location_type=3) or boarding areas (location_type=4).

Describe the new validation rule
We should add a rule that would trigger a MissingStopNameNotice if:

• (location_type has values 0, 1 or 2) AND (stop_name is missing) for a line in stops.txt

Error vs warning
ERROR