Release 4.8.1

* Make specific Checkout exceptions extend `CheckoutException`
* Removed deprecated Events and `CountryCode` string references
* Added @Builder.Default to `PaymentRequest` metadata (FOUR)
* Added `name` and `city` attributes to BillingDescriptor (FOUR)
* Removed redundant enum lookup methods
* Minor fixes on CVV card payment mappings

gradle.properties

@@ -1,5 +1,5 @@
 group=com.checkout
-version=4.7.0
+version=4.8.1
 
 maven2_url=https://oss.sonatype.org/service/local/staging/deploy/maven2/
 snapshot_url=https://oss.sonatype.org/content/repositories/snapshots/