yspec 0.6.2

Breaking changes

• nm_input() was significantly refactored to produce output more typically seen
  in practice as well as adding some convenience features (#150).
  • the default output is now wide format
  • data set labels can get renamed with <new name> = <old name> syntax, passed
    under ...
  • columns with type <character> are dropped by default
  • the cat argument was renamed .cat
  • the .drop argument was added to indicate a group of data items to drop
    from the problem
  • the previous long output can be recreated using .long = TRUE
  • the .decodes argument was added to control appearance of categorical data
    decode information in the long output