DictModeViewSet moved to new folder for cleaner code

rex/models/location/location.py

 from django.db import models
 from rest_framework import serializers, viewsets, permissions
+from rex.models.tools import DictModeViewSet
 
 # Data model based on : https://unstats.un.org/unsd/methodology/m49/overview/
 
@@ -29,25 +30,6 @@ class City(models.Model):
 API RELATED STUFF BELLOW
 """
 
-# TODO move somewhere else
-
-
-class DictModeViewSet(viewsets.ModelViewSet):
-    """
-    ViewSet that renders data as dict with keys corresponding to the model
-    primary key. Instead of list.
-    """
-
-    def list(self, request, *args, **kwargs):
-        response = super(viewsets.ModelViewSet, self).list(  # pylint: disable=E1003
-            request, *args, **kwargs)  # call the original 'list'
-        pk_attr_name = self.serializer_class.Meta.model._meta.pk.name
-        response.data = {
-            d[pk_attr_name]: d for d in response.data
-        }
-        return response
-
-
 class CountrySerializer(serializers.ModelSerializer):
 
     class Meta:

rex/models/tools/DictModeViewSet.py

+from rest_framework import viewsets
+
+
+class DictModeViewSet(viewsets.ModelViewSet):
+    """
+    ViewSet that renders data as dict with keys corresponding to the model
+    primary key. Instead of list.
+    """
+
+    def list(self, request, *args, **kwargs):
+        response = super(viewsets.ModelViewSet, self).list(  # pylint: disable=E1003
+            request, *args, **kwargs)  # call the original 'list'
+        pk_attr_name = self.serializer_class.Meta.model._meta.pk.name
+        response.data = {
+            d[pk_attr_name]: d for d in response.data
+        }
+        return response

rex/models/tools/__init__.py

+from .DictModeViewSet import DictModeViewSet  # noqa: F401