c3nav export: include room's slug, too

src/api/views/maps.py

@@ -197,6 +197,7 @@ class C3NavExportView(ConferenceSlugMixin, APIView):
                     'type': 'room',
                     'id': str(room.pk),
                     'name': room.name,
+                    'slug': room.slug,
                     'is_official': room.is_official,
                     'in_public_fahrplan': room.is_public_fahrplan,
                     'description': {'de': room.description_de, 'en': room.description_en},