Added support for parsers.
Added support for specifying a city's parser.
Added parser code for London.
When a station latest's update timestamp is unknown, compare every attribute to determine if it has been updated.
Use the helper methods for increasing the values for the summary.
Removed debugging statement.
Fixed oversight from previous refactorings.
Fixed incorrect usage of a helper method.
Fixed a bug where the created and updated counts would be increased when adding a station.
Timestamps of 0 shouldn't be parsed into a valid date.
Added a JSON parser and support for Melbourne.
Merge branch 'dev'