all: release v0.14.0

This change will be tagged v0.14.0

Change-Id: I2be14c8285a073dca6973a92a95b7171006890ea
Reviewed-on: https://code-review.googlesource.com/c/google-api-go-client/+/48492
Reviewed-by: Jean de Klerk <deklerk@google.com>
diff --git a/CHANGES.md b/CHANGES.md
index b3b722b..de29b4f 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,16 @@
+# v0.14.0
+
+- Fix for setting custom HTTP headers in the absence of UserAgent.
+
+- Add a client option for disabling telemetry such as OpenCensus.
+
+- Performance improvements to google.golang.org/api/support/bundler.
+
+- Various updates to autogenerated clients.
+
+_Please note:_ the release version is not indicative of an individual client's
+stability or version.
+
 # v0.13.0
 
 - Changes to how media path redirection is handled in generated code.