joi 2.0 is a complete rewrite of the previous version. While largely backward compatible, it includes a few changes that are
not as well as a large number of bug fixes that dramatically changes existing behavior. The following is an incomplete list of changes.
Please test your existing validation rules to ensure they behave as expected with this new version.

• Joi.types and Joi.Types deprecated - use Joi.string() etc. instead.
• Uppercase type names deprecated - use lowercase function names instead.
• Top level global config options no longer supported (e.g. { languagePath: './file.json' }). Use the .options() method instead.
• noShortCircuit() no longer supported - use the abortEarly option instead.
• Options renamed:
  • saveConversions changed to modify.
  • skipConversions changed to convert (with reversed meaning).
  • stripExtraKeys changed to stripUnknown.
  • allowExtraKeys changed to allowUnknown.
  • In rename() options:
    • deleteOrig changed to move.
    • allowMult changed to multiple.
    • allowOverwrite changed to override.
• nullOk() and emptyOk() are deprecated - use allow(null) and allow('') instead.
• number().float() no longer supported.
• Completely new internal representation of the data. If you were accessing _variables, your code is most likely broken now. Use describe() instead.
• string().alphanum() no longer allows spaces and underscores and does not take an arguement.
• string().date() no longer supported - use new date() type.
• deny() deprecated - use invalid() instead.
• array().includes() and array.excludes() now validates correctly (not just the base type).
• allow(), valid(), and invalid() values are now compared against the original and converted values (not just after conversion).
• string().min() no longer implies required().