Barfing if load_geojson() doesn't have a filename argument
Barfing if input GeoJSON file not found
Adding the last_update attribute to the Location class
[t] testing Location attribute default values
Removing superfluous "location" prefix in Location attributes
[lib] Using autodie (just in case...)
Correcting add_entry() after Location attribute name simplification
First implementation of load_geojson()

At present only loading the name attribute, but it does basically what we
need it to do.
Removing json-loading code from list_entries()

The loading is now handled by load_geojson().
Renaming load_geojson() -> load_locations()

This is a better description of the method's purpose.