Bugfix/dates with zero as day return no error#30

lucamug wants to merge 2 commits intortfeldman:masterrtfeldman/elm-iso8601-date-strings:masterfrom

lucamug:bugfix/dates-with-zero-as-day-return-no-errorlucamug/elm-iso8601-date-strings:bugfix/dates-with-zero-as-day-return-no-errorCopy head branch name to clipboard