In progress PriorityQueue class and tests. Not working yet... pop tests are failing in mysterious ways.
Fixed issue where PrioritizedItem's comparitors weren't working properly by decorating the PrioritizedItem class with @total_ordering. Tests are decent and all pass.
Cleaned up some unnecessary code and comments. Fixed __str__ methods to be more clear. Tests still pass.
Merge branch 'master' of https://github.com/sazlin/data-structures