Credit Card returning null when valid

[chamini2]

Context

• node version: v4.4.3
• joi version: 9.0.0
• used with (hapi, standalone, ...): hapi

What are you trying to achieve or the steps to reproduce ?

Describe your issue here, include schemas and inputs you are validating if needed.

let schema = Joi.string().creditCard()
schema.validate('4111111111111111')

Which result you had ?

{ error: null, value: null }

What did you expect ?

{ error: null, value: '4111111111111111' }