v1.3.0

Added

• Retry.withMaxDelay(Duration) - caps every backoff delay (applied after the
  multiplier and jitter). Without a cap the delay grows unboundedly and, for a
  large multiplier or many attempts, multiplier^n overflows to an endless
  wait; the cap keeps waits bounded.
• Retry.onRetry(RetryListener) and the new RetryListener functional
  interface - called right before each retry with the 1-based failed attempt
  number, its failure and the delay about to be waited. Works for both
  execute and executeAsync; not called after the final attempt or for
  non-retryable failures. A listener that throws aborts retrying (propagated
  by execute, completes the future exceptionally for executeAsync).