Updating to reflect new datahub structure

[dlcomeaux]

The CMAP datahub is now back online, but with a new structure. I am not sure whether and how we can use direct links for ZIP files anymore for some of the shapefiles that the code previously extracted. This would be a good topic for exploration - it appears that we might need to use JSON instead, which has an API call, but I'm not certain if there are other options.