+1 SWIFT/BIC payment type

Uppercasing Swift/Bic values seems to be common practice, even though [ISO-9362 specification](http://www.swift.com/assets/swift_com/documents/products_services/BIC2014_white_paper_57047_june2014.pdf) & the related [Wikipedia Page](http://en.wikipedia.org/wiki/ISO_9362) both avoid giving particular indications on that matter.

I used the new Faker's Regex-based generator, and I presume any unit test may be useless here, since `BaseProvider::regexify()` is already test-covered.