Call self.prefix= and self.source_reader_class since calling without self only sets local variables per Ruby
Make prefix and source reader class instance variables on the class so they don't change the parent
Actually send the writer so that the attribute, umm, writes
Update the ResourcSets README to show we need to use the self versions of the writers so we don't just set a local variable and that we need to put the module on the SourceReader
Add the first cut of the SpatialDataRepository ResourceSet