Refactored RouteComparison.compare_and_update() for better readability
Refactored RouteComparison.compare_and_update() for better readability

Previously used a nested try and except if a destination ip or source
and destination ip could not be found within the loaded data store
(self.data_store).

Now using dictionary setdefault method within a single try and except
to update the dictionary accordingly.

spgreen/psTrace