chore(storage): release storage/v1.12.0 (#2907)

diff --git a/internal/version/version.go b/internal/version/version.go
index c49a226..5be2c68 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 = "20200921"
+const Repo = "20200922"
 
 // Go returns the Go runtime version. The returned string
 // has no whitespace.
diff --git a/storage/CHANGES.md b/storage/CHANGES.md
index f69ef9d..1736278 100644
--- a/storage/CHANGES.md
+++ b/storage/CHANGES.md
@@ -1,5 +1,12 @@
 # Changes
 
+## v1.12.0
+- V4 signed URL fixes:
+  - Fix encoding of spaces in query parameters.
+  - Add fields that were missing from PostPolicyV4 policy conditions.
+- Fix Query to correctly list prefixes as well as objects when SetAttrSelection
+  is used.
+
 ## v1.11.0
 - Add support for CustomTime and NoncurrentTime object lifecycle management
   features.