Changelog
Source:NEWS.md
    fyr 0.0.2
- Add count_case().
- Update documents following roxygen2 style.
- Add new arguments to function is_same_dates()for identifying keys to sort data
- Add new arg keep = FALSEinget_valid_codes()
NEWS.md
    count_case().is_same_dates() for identifying keys to sort datakeep = FALSE in get_valid_codes()