google-cloud-pubsub 0.28.0

This release entails a complete rewrite of the Pub/Sub library, introducing non-blocking publish and subscribe functions. As this is a from-scratch rewrite, note that it is very much a breaking change.

This also entails that a "changelist" has limited value, but the highlights:

• The unified pubsub.Client object has been replaced by a PublisherClient and SubscriberClient.

• The publish method (on PublisherClient) now has the following signature:

  def publish(self, str: topic_name, bytes: data, **attributes) -> Future:

• The subscriber method (on SubscriberClient) now has the following signature:

  def subscriber(self, str: subscription_name) -> Policy:

  The returned object here has an open method, which accepts a callback, which receives a Message as its only argument:

  def open(self, Callable: callback):

For more details, please consult the documentation.