Rename constants to populations

This is a better name for the module because it’s:
- not just constants, there’s a method in here now
- only stuff to do with populations, not other kinds of constants

app/broadcast_areas/__init__.py

@@ -1,8 +1,8 @@
 from notifications_utils.serialised_model import SerialisedModelCollection
 from werkzeug.utils import cached_property
 
-from .constants import CITY_OF_LONDON
 from .polygons import Polygons
+from .populations import CITY_OF_LONDON
 from .repo import BroadcastAreasRepository
 
 

app/broadcast_areas/create-broadcast-areas-db.py

@@ -7,7 +7,8 @@ from pathlib import Path
 import geojson
 from notifications_utils.formatters import formatted_list
 
-from constants import (
+from polygons import Polygons
+from populations import (
     BRYHER,
     CITY_OF_LONDON,
     MEDIAN_AGE_RANGE_UK,
@@ -15,7 +16,6 @@ from constants import (
     SMARTPHONE_OWNERSHIP_BY_AGE_RANGE,
     estimate_number_of_smartphones_for_population,
 )
-from polygons import Polygons
 from repo import BroadcastAreasRepository
 
 source_files_path = Path(__file__).resolve().parent / 'source_files'

tests/app/broadcast_areas/test_broadcast_area.py

@@ -4,7 +4,7 @@ from app.broadcast_areas import (
     BroadcastAreasRepository,
     broadcast_area_libraries,
 )
-from app.broadcast_areas.constants import CITY_OF_LONDON
+from app.broadcast_areas.populations import CITY_OF_LONDON
 
 
 def test_loads_libraries():