ONAP: Add Dublin branch to doc project

Change-Id: I5b721b720d9dd388f44cadcfa415f6de3551bad3
diff --git a/jjb/onap/doc/doc-rebase.yaml b/jjb/onap/doc/doc-rebase.yaml
index d925a7e..b268fb0 100644
--- a/jjb/onap/doc/doc-rebase.yaml
+++ b/jjb/onap/doc/doc-rebase.yaml
@@ -27,6 +27,8 @@
     stream:
       - master:
           branch: '{stream}'
+      - dublin:
+          branch: '{stream}'
 
     jobs:
       - 'onap-{project-name}-{stream}-rebase'