Replace Missing 'matchCardType()' Entry Point

The public API had a ValidateCreditCard.matchCardType(long) entry point
that I removed in a previous commit. Restore that entry point with an
implementation that checks card number formats against our regular
expressions and checks the range (number of digits).
Add Basic Maven Deployment Support

Build the AAR and all supporting Maven Central ready materials in the
build directory.

- The AAR will be in ex.
build/artifacts/1.0.1/com/paymentkit/paymentkit-android/1.0.1/paymentkit
-android-1.0.1.aar