Adding option to include invoiceNumber in PayPalPayment.
Adding option to include invoiceNumber in PayPalPayment for the js-helper
Removing extra data checking type, and setting invoiceNumber as string
Fixing setting of invoiceNumber
bump the version number to 2.2.0
Merge pull request #32 from miche-atucha/master

Adding option to include invoiceNumber in PayPalPayment.