Allow empty exchange name in consumer configuration #182
Description
RabbitMQ server declares a default exchange that is named as an empty string (see https://www.rabbitmq.com/tutorials/amqp-concepts.html#exchange-default). The bundle does not allow an empty string in producer configuration (exchange_options: { name: '' }) even it would be fully supported by AMQP Protocol. It would be useful if also default exchange could be configured for producers - actually also type could be omitted in that case.
NB: The whole exchange_options could be omitted and could default to the AMQP default exchange: exchange_options: { name: '', type: direct }