all: add test info to release instructions

Adds the policy of not releasing when integration tests
are failing to the instructions in RELEASING.md.

Change-Id: I3930384c45461c2e5a6a0ce909ce067bc685954f
Reviewed-on: https://code-review.googlesource.com/c/gocloud/+/56050
Reviewed-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Cody Oss <codyoss@google.com>
diff --git a/RELEASING.md b/RELEASING.md
index 3fb49c4..7a8a5fb 100644
--- a/RELEASING.md
+++ b/RELEASING.md
@@ -90,8 +90,17 @@
 `cloud.google.com/go` has no impact on any of the submodules, and vice-versa.
 They are released entirely independently.
 
+# Test failures
+
+If there are any test failures in the Kokoro build, releases are blocked until
+the failures have been resolved.
+
 # How to release `cloud.google.com/go`
 
+1. Check for failures in the
+   [continuous Kokoro build](go/google-cloud-go-continuous). If there are any
+   failures in the most recent build, address them before proceeding with the
+   release.
 1. Navigate to `~/code/gocloud/` and switch to master.
 1. `git pull`
 1. Run `git tag -l | grep -v beta | grep -v alpha` to see all existing releases.
@@ -126,6 +135,11 @@
 
 (these instructions assume we're releasing `cloud.google.com/go/datastore` - adjust accordingly)
 
+1. Check for failures in the
+   [continuous Kokoro build](go/google-cloud-go-continuous). If there are any
+   failures in the most recent build, address them before proceeding with the
+   release. (This applies even if the failures are in a different submodule from the one
+   being released.)
 1. Navigate to `~/code/gocloud/` and switch to master.
 1. `git pull`
 1. Run `git tag -l | grep datastore | grep -v beta | grep -v alpha` to see all