Remove 'eer' as lookup for the CustomFinderManager
Remove 'eer' as lookup for the CustomFinderManager

Using ONSUD allowed us to route requests to custom PSFs based on any
GSS code. Now the look-up has to be by Council. Which means there
should be a CustomFinder for each local authority.

DemocracyClub/UK-Polling-Stations,DemocracyClub/UK-Polling-Stations,DemocracyClub/UK-Polling-Stations