Proposed changes

The exchange is hardcoded with empty string in rabbitmq executor, this PR allow user to customize exchange in executor_config.

{
  "executor": "rabbitmq",
  "executor_config": {
    "url": "amqp://guest:guest@localhost:5672/",
    "exchange": "amq.default",
    "queue.name": "test",
    "queue.create": "true",
    "queue.durable": "true",
    "queue.auto_delete": "false",
    "queue.exclusive": "false",
    "message.content_type": "application/json",
    "message.delivery_mode": "2",
    "message.messageId": "4373732772",
    "message.body": "{\"key\":\"value\"}"
  }
}

Types of changes

What types of changes does your code introduce?
Put an x in the boxes that apply

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)