chore: release pubsublite 0.4.0 (#3412)

* chore: release pubsublite 0.4.0

pubsublite/CHANGES.md

@@ -1,5 +1,24 @@
 # Changes
 
+## [0.4.0](https://www.github.com/googleapis/google-cloud-go/compare/pubsublite/v0.3.0...v0.4.0) (2020-12-09)
+
+
+### Features
+
+pubsublite/internal/wire implementation:
+
+* **pubsublite:** assigning subscriber ([#3238](https://www.github.com/googleapis/google-cloud-go/issues/3238)) ([d1c03da](https://www.github.com/googleapis/google-cloud-go/commit/d1c03dae383f5a175e4237d5f46dc1bdc2cd33f0))
+* **pubsublite:** committer ([#3198](https://www.github.com/googleapis/google-cloud-go/issues/3198)) ([ecc706b](https://www.github.com/googleapis/google-cloud-go/commit/ecc706b03079c6521a31e1066b00677aaf51e7dd))
+* **pubsublite:** receive settings ([#3195](https://www.github.com/googleapis/google-cloud-go/issues/3195)) ([bd837fc](https://www.github.com/googleapis/google-cloud-go/commit/bd837fc9aad4181b8aa574e41341000755875eca))
+* **pubsublite:** routing publisher ([#3277](https://www.github.com/googleapis/google-cloud-go/issues/3277)) ([88e5466](https://www.github.com/googleapis/google-cloud-go/commit/88e546600c7d4f7570530aa72355f51f44187890))
+* **pubsublite:** single and multi partition subscribers ([#3221](https://www.github.com/googleapis/google-cloud-go/issues/3221)) ([299b803](https://www.github.com/googleapis/google-cloud-go/commit/299b803aaee9a0dc0b2ec8c81fac66341045b8b2))
+* **pubsublite:** single partition publisher ([#3225](https://www.github.com/googleapis/google-cloud-go/issues/3225)) ([4982eeb](https://www.github.com/googleapis/google-cloud-go/commit/4982eeb32ebe85de211ae09d13fdaf6140d9e115))
+
+
+### Bug Fixes
+
+* **pubsublite:** fixed return value of AdminClient.TopicSubscriptions ([#3220](https://www.github.com/googleapis/google-cloud-go/issues/3220)) ([f37f118](https://www.github.com/googleapis/google-cloud-go/commit/f37f118c87d4d0a77a554515a430ae06e5852294))
+
 ## [0.3.0](https://www.github.com/googleapis/google-cloud-go/compare/pubsublite/v0.2.0...v0.3.0) (2020-11-10)