pubsub: release pubsub/v1.3.1

This commit will be tagged pubsub/v1.3.1

Change-Id: I08666f88db63245cb55bfc69ca82e869e50edc0f
Reviewed-on: https://code-review.googlesource.com/c/gocloud/+/53230
Reviewed-by: Cody Oss <codyoss@google.com>
Reviewed-by: kokoro <noreply+kokoro@google.com>
diff --git a/internal/version/version.go b/internal/version/version.go
index 2fc58c3..024aed5 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 = "20200228"
+const Repo = "20200312"
 
 // Go returns the Go runtime version. The returned string
 // has no whitespace.
diff --git a/pubsub/CHANGES.md b/pubsub/CHANGES.md
index e9186a4..49de654 100644
--- a/pubsub/CHANGES.md
+++ b/pubsub/CHANGES.md
@@ -1,5 +1,10 @@
 # Changes
 
+## v1.3.1
+
+- Fix bug with removing dead letter policy from a subscription
+- Set default value of MaxExtensionPeriod to 0, which is functionally equivalent
+
 ## v1.3.0
 
 - Update cloud.google.com/go to v0.54.0