all: release v0.13.0

This change will be tagged v0.13.0

Change-Id: Ibf1fe24f558eeb6fcc7363858fd2c973746fcd8b
Reviewed-on: https://code-review.googlesource.com/c/google-api-go-client/+/47513
Reviewed-by: Jean de Klerk <deklerk@google.com>
Reviewed-by: kokoro <noreply+kokoro@google.com>

CHANGES.md

diff --git a/CHANGES.md b/CHANGES.md
index c40dafc..b3b722b 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,12 @@
+# v0.13.0
+
+- Changes to how media path redirection is handled in generated code.
+
+- Various updates to autogenerated clients.
+
+_Please note:_ the release version is not indicative of an individual client's
+stability or version.
+
 # v0.12.0
 
 - Various updates to autogenerated clients.