3.1.0

• Fixed: If an exception occurs within the rate limiter implementation, it will be logged and reported but we try to continue sending the notification itself (irrespective of any rate limit that might have applied). This avoids the possibility of silently causing notifications to not be dispatched at all.
• New: Added config option unique_notification_strategy to allow choosing the mechanism to use when determining whether a notification is unique (in case serialize() is not appropriate).