[ZA] Fix intermittent problem with Ward Councillor lookups

This code was making a bad assumption about the order of things in the
response from the code4sa mapit API. It was assuming that ward would
always come first, and then municipality. But it seems that was not the
case, the order of results from mapit is actually random and shouldn't
be relied on.

So this change adds some extra checks to ensure we're using the correct
bits of the JSON for the ward and municipality.

pombola/south_africa/views/geolocalization.py

@@ -96,8 +96,15 @@ def get_ward_councillors(self, location):
         mapit_json = r.json()
         if not mapit_json:
             return []
-        ward_id = mapit_json.values()[0]['codes']['MDB']
-        muni_id = mapit_json.values()[1]['codes']['MDB']
+        ward = None
+        muni = None
+        for item in mapit_json.values():
+            if item['type_name'] == 'Ward':
+                ward = item
+            elif item['type_name'] == 'Municipality':
+                muni = item
+        ward_id = ward['codes']['MDB']
+        muni_id = muni['codes']['MDB']
 
         # Then find the ward councillor from that ward ID. There
         # should only be one at the moment, but make it a list in case