dateutil 2.7.3

Data updates

• Update tzdata to 2018e. (gh pr #710)

Bugfixes

• Fixed an issue where decimal.Decimal would cast NaN or infinite value in a parser.parse, which will raise decimal.Decimal-specific errors. Reported and fixed by @amureki (gh issue #662, gh pr #679).
• Fixed a ValueError being thrown if tzinfos call explicity returns None. Reported by @pganssle (gh issue #661) Fixed by @parsethis (gh pr #681)
• Fixed incorrect parsing of certain dates earlier than 100 AD when repesented in the form "%B.%Y.%d", e.g. "December.0031.30". (gh issue #687, pr #700)
• Fixed a bug where automatically generated DTSTART was naive even if a specified UNTIL had a time zone. Automatically generated DTSTART will now take on the timezone of an UNTIL date, if provided. Reported by @href (gh issue #652). Fixed by @absreim (gh pr #693).

Documentation changes

• Corrected link syntax and updated URL to https for ISO year week number notation in relativedelta examples. (gh issue #670, pr #711)
• Add doctest examples to tzfile documentation. Done by @weatherpattern and @pganssle (gh pr #671)
• Updated the documentation for relativedelta. Removed references to tuple arguments for weekday, explained effect of weekday(_, 1) and better explained the order of operations that relativedelta applies. Fixed by @kvn219 @huangy22 and @ElliotJH (gh pr #673)
• Added changelog to documentation. (gh issue #692, gh pr #707)
• Changed order of keywords in rrule docstring. Reported and fixed by @rmahajan14 (gh issue #686, gh pr #695).
• Added documentation for dateutil.tz.gettz. Reported by @pganssle (gh issue #647). Fixed by @weatherpattern (gh pr #704)
• Cleaned up malformed RST in the tz documentation. (gh issue #702, gh pr #706)
• Changed the default theme to sphinx_rtd_theme, and changed the sphinx configuration to go along with that. (gh pr #707)
• Reorganized dateutil.tz documentation and fixed issue with the dateutil.tz docstring. (gh pr #714)

Misc

• GH #674, GH #688, GH #699