pubsub: Initial import of pubsub.
Merge branch 'master' into pubsub-init
Merge branch 'master' into pubsub-init
Merge branch 'master' into pubsub-init
Merge branch 'master' into pubsub-init
pubsub: Fix the API name.
Drop support for int64 label values and minor readability improvements.
Remove the unnecessary lock.
pubsub: Fix pub sub import path.
pubsub: Remove message listener.
pubsub: Support only string label values, cast int values to string.
pubsub: Rename Subscription to SubClient, Topic to TopicClient.
pubsub: Drop time.Duration from deadline values.
pubsub: Fix misleading docs.
pubsub: Use time.Duration for deadline values. Make sure they are not more precise than a second.