added contrib/spring/README.md to list of README files in RELEASING.md
diff --git a/RELEASING.md b/RELEASING.md
index 559b7ef..48ad850 100644
--- a/RELEASING.md
+++ b/RELEASING.md
@@ -226,6 +226,7 @@
   contrib/http_util/README.md
   contrib/log_correlation/stackdriver/README.md
   contrib/monitored_resource_util/README.md
+  contrib/spring/README.md
   contrib/zpages/README.md
   exporters/stats/prometheus/README.md
   exporters/stats/signalfx/README.md