Rethrow GSON parsing exceptions in service implementations as
ServiceExceptions
Made HttpClientStoryService tests more explicit by inlining inputs to
visually correlate with expectations
Added missing HttpClientStoryService tests
Added Queue test
Used non-default value in tests
Added Story test
Added GSON constructor tests
Used better values in default constructors to honour non-null invariants
Chained default constructors to normal ones
Renamed Queue.getStoryCount and added merged flag
Formatted source
Added Queue.getStoryCount tests
Added Preconditions test
Simplified web service URLs in tests
Renamed apiUrl to serviceUrl