Lots of changes to database models.  Now supports CRIS, and arbitrary divisions.
Added to populate methods - can now load LSOA, MSOA, boroughs, wards.
Modified initial migration because so much has changed.  From now on, use partial migrations.
Added view to compare CAD with CRIS and a method for plotting
changed requirements, so don't forget to pip install.
Added lookup table for LSOA to borough etc.