Refactor tests.db.fake_data.factories into a package

tests/db/fake_data/factories/customers.py

@@ -0,0 +1,16 @@
+"""Factory to create `Customers` instances."""
+
+import factory
+from factory import alchemy
+
+from urban_meal_delivery import db
+
+
+class CustomerFactory(alchemy.SQLAlchemyModelFactory):
+    """Create instances of the `db.Customer` model."""
+
+    class Meta:
+        model = db.Customer
+        sqlalchemy_get_or_create = ('id',)
+
+    id = factory.Sequence(lambda num: num)  # noqa:WPS125