chore(pubsub): release v1.5.0 (#2555)

* chore(pubsub): release v1.5.0
diff --git a/internal/version/version.go b/internal/version/version.go
index 556642f..3328019 100644
--- a/internal/version/version.go
+++ b/internal/version/version.go
@@ -26,7 +26,7 @@
 
 // Repo is the current version of the client libraries in this
 // repo. It should be a date in YYYYMMDD format.
-const Repo = "20200701"
+const Repo = "20200706"
 
 // Go returns the Go runtime version. The returned string
 // has no whitespace.
diff --git a/pubsub/CHANGES.md b/pubsub/CHANGES.md
index 2217f2c..aab62a4 100644
--- a/pubsub/CHANGES.md
+++ b/pubsub/CHANGES.md
@@ -1,5 +1,13 @@
 # Changes
 
+## v1.5.0
+
+- Add support for subscription detachment.
+- Add support for message filtering in subscriptions.
+- Add support for RetryPolicy (server-side feature).
+- Fix publish error path when ordering key is disabled.
+- Fix panic on Topic.ResumePublish method.
+
 ## v1.4.0
 
 - Add support for upcoming ordering keys feature.