Data updates
- Updated tzdata version to 2018d.
Bugfixes
- Fixed issue where parser.parse would occasionally raise
decimal.Decimal-specific error types rather than ValueError. Reported by
@amureki (gh issue #632). Fixed by @pganssle (gh pr #636). - Improve error message when rrule's dtstart and until are not both naive or
both aware. Reported and fixed by @ryanpetrello (gh issue #633, gh pr #634)