SVM (#14) and C5.0 (#9) models were added.
Clipboard access is enabled in all use_*() functions
using the clipboard = TRUE argument (#12).
Use new all_nominal_predictors() selector
(#17).
Updated version requirements for dependencies.
Added use_cubist().
Fixed bug in handling of variables for
step_string2factor()
NEWS.md file to track changes to the
package.