v1.0.2

Added

• recode_to_pmml now throws an error if the database the user wants to
  generate the PMML file for (the database_name parameter) is not present in
  the variables sheet
• recode_to_pmml now throws an error when a recoded variable and one of its
  start variables are named the same
• recode_to_pmml now throw an error if there's no entry for a model steps
  file in the model export file
• recode_to_pmml now throws an error if the entry for the model steps file
  cannot be found
• Added the devtools package to the DESCRIPTION file's Suggests field so
  renv can install it