ipumsr 0.6.3

• The ability to read an IPUMS DDI file contained within a zip archive using
  read_ipums_ddi() has been deprecated. Users must now load DDI files by
  providing the direct path to the uncompressed .xml file.

  This resolves an inconsistency between the behavior
  of read_ipums_micro_*() functions when provided a DDI file path as compared to
  an ipums_ddi object created with read_ipums_ddi().

• The ability to read IPUMS files by providing the path to their containing
  directory has been deprecated. This affects:

  • read_nhgis()
  • read_ipums_sf()
  • read_nhgis_codebook()
  • read_ipums_ddi()
  • ipums_list_files()

  These functions now require either a zip archive (with the exception of
  read_ipums_ddi()—see above) or a direct file path as input.

  This has the consequence that read_ipums_sf() with bind_multiple = TRUE
  requires a zip archive as input if multiple files are to be read and combined.

• Documentation updates for clarity