storage: release storage/v1.8.0

Change-Id: I8ec5b8ab1f18b2df5a61df77e8b9b60305d0af03
Reviewed-on: https://code-review.googlesource.com/c/gocloud/+/56310
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Cody Oss <codyoss@google.com>
Reviewed-by: Frank Natividad <franknatividad@google.com>
diff --git a/internal/version/version.go b/internal/version/version.go
index aafee13..fc71573 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 = "20200506"
+const Repo = "20200512"
 
 // Go returns the Go runtime version. The returned string
 // has no whitespace.
diff --git a/storage/CHANGES.md b/storage/CHANGES.md
index 295f5f2..2fe29e0 100644
--- a/storage/CHANGES.md
+++ b/storage/CHANGES.md
@@ -1,5 +1,8 @@
 # Changes
 
+## v1.8.0
+- Add support for V4 signed post policies.
+
 ## v1.7.0
 - V4 signed URL support:
   - Add support for bucket-bound domains and virtual hosted style URLs.