BREAKING CHANGE: some methodes in Event and MoonPhase have been dropped
in favor of `enum.Enum`'s `name` and `value` properties.

BREAKING CHANGE: the JSON format has deeply changed to enhance its
consistency

BREAKING CHANGE: the --day, --month and --year arguments have been removed in the
favor of a single one.

BREAKING CHANGE: JSON format now returns the moon phase as an object
instead of a string