Fix terraform-google-modules#16.

scripts/wait-for-jenkins.sh

@@ -1,5 +1,5 @@
 #!/bin/bash
-# Copyright 2018 Google LLC
+# Copyright 2019 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -13,6 +13,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+set -e
+
+if [ -n "${GOOGLE_APPLICATION_CREDENTIALS}" ]; then
+    export CLOUDSDK_AUTH_CREDENTIAL_FILE_OVERRIDE=${GOOGLE_APPLICATION_CREDENTIALS}
+fi
+
 PROJECT=$1
 ZONE=$2
 INSTANCE_NAME=$3