finbif v0.6.6

NEW FEATURES

• New option to exclude all records with any NA values for any of the
  selected variables added to finbif_occurrence.

MINOR IMPROVEMENTS

• The warning/error message returned when an invalid taxon is
  requested with finbif_occurrence has been made more detailed,
  warning the user they may be using synonyms or other invalid taxon
  names.

BUG FIXES

• Fix applied for a print method error triggered by clashing class
  names.

• Fixed issue with ordering by some variables.