remove validationMode element from API calls that do not support it

The CIM API only supports the validationMode element on certain methods.
Quoting the docs:

"The validationMode parameter enables you to generate a test transaction at the
time you create or update a customer profile.

The functions createCustomerProfileRequest,
createCustomerPaymentProfileRequest, updateCustomerPaymentProfileRequest,
validateCustomerPaymentProfileRequest all include a validationMode parameter"

Including it in other methods results in an error.
Merge pull request #5 from rhesa/master

Remove validationMode element from unsupported API methods