PostalCode does not use the correct events

[paulpdaniels]

The PostalCode component has a bunch of events defined on it but none of them match up with what is being fired from the underlying StripeElement.

Most notably the "change" event is missing (instead there is complete but there doesn't appear to be any logic to actually emit that).

Also could you export the StripeElement as part of the lib build? It isn't part of the exports it is isn't even possible to create a custom StripeElement to work around the buggy PostalCode.

[softbeehive]

Thanks for fixing it, I just published v0.2.7