This relates #9

Added DST example using only the builtin datetime module.

Fix typos

This relates #6

Fixes #170 #171

fix missing encoding parameter in setup.py

Spelling.

rel  #162

Closes: taichino/croniter#162

C901 is normally not checked because max-complexity is not set, but
if the user has max-complexity set in their user-wide .config/flake8,
this will prevent false positives.

when crontab day only one day, but last month not has the day, example crontab expression: 0 6 30 3 *

- Remove _get_last_weekday_of_month and replaced it with
  _get_nth_weekday_of_month() and avoid making multiple calls to the calendar
  module when both '#' and 'L' syntax are used at the same time.
- Updated unittests for get_last_weekday_of_month() to instead simply call
  _get_nth_weekday_of_month()[-1].
- Create unit test for new function.

Note that _get_nth_weekday_of_month() is a good candidate for caching as
repeated calls to calendar add up over time, especially when evaluating
multiple cron expressions concurrently.