v2.3 Enforce TLS 1.2

Functional changes

1. Change in way how the source attribute is handled. See: https://github.com/xola/stripe/pull/5/files#diff-faba19ab9ebdb4968e8a6b8ea2456511R201
2. TLS v1.2 enforced https://github.com/xola/stripe/pull/5/files#diff-f1a888a4f0baadb508b5a2bd87ed09c6R150 (See Stripe's blog post)

v2.2.1 Update statement descriptor param name

The old version of the Stripe API used the param statement_description whereas the new version uses statement_descriptor. This release allows for seamlessly switching between different stripe versions and still having the statement descriptor work correctly.

v2.1.0 Allow zip code and CVV in card present transactions

Earlier, if card swipe data was provided, we did not send any other data to Stripe. This sometimes resulted in higher decline rates. To mitigate these declines, we now allow zip and CVV to be sent even for card present transactions.