EnsurePublisher handles no-route error

[furdarius]

• EnsurePublisher will publish messages with mandatory flag and return error if no queue is bound that matches the routing key. (https://www.rabbitmq.com/amqp-0-9-1-errata.html#section_17) This will avoid losing messages when the box exists without a queue.
• RetryPublisher creation extended with functional options (e.g. max publishing attempt and flexible delay).