Add an `async` function to publish messages

[abompard]

Add an asyncio-based publish function.

[Freedisch]

I assume you are referring to the publish function present in the API. I will check it and run tests to ensure nothing breaks after the changes.

def publish(message, exchange=None, timeout=30):
    """
    Publish a message to an exchange.

[abompard]

This is actually very far from a simple issue, I wouldn't start with this one.

[bajajharsha]

Hi, I'd like to work on this issue

[abompard]

Please see the comment above @bajajharsha .

[bajajharsha]

@abompard Can you guide me on which one is comparatively an easier issue that I can start with?

[nwekealex65]

@abompard I do like to work on this, I have experience working with asyncio