Changes

🕐 Adds support for java.time.Instant 🕐

This PR adds support for java.time.Instant for creating and verifying JWTs. Key points to note:

• Instant support is added to Date functionality; customers using Date can continue to do so.
• Additional methods added to interfaces have a default implementation using the underlying Date methods
• Internal implementation updated to use Instant for its improved functionality

Note: This PR does not include support for custom claim validation of type Instant. A separate PR will add support for this as well as address the current issue of Date-based claim validation not accounting for date/time claims being serialized as seconds since the epoch.

References

https://docs.oracle.com/javase/8/docs/api/java/time/Instant.html

Testing

Existing unit tests provide good coverage, and tests added for new methods