JJB cleanups for VOLTHA.

Misc/
  o yaml lint clenaups
  o Remove prototype voltha-2.{9,10,11} job placeholders.
  o Replace mainatiner email address (Matteo) with build system group.

Change-Id: I37e1175f56042632753b75c849dbaf07f74bd284
diff --git a/jjb/verify/att-workflow-driver.yaml b/jjb/verify/att-workflow-driver.yaml
index 91b0514..f244a66 100644
--- a/jjb/verify/att-workflow-driver.yaml
+++ b/jjb/verify/att-workflow-driver.yaml
@@ -25,6 +25,6 @@
     name: 'publish-att-workflow-driver-jobs'
     jobs:
       - 'docker-publish':
-          maintainers: "teo@opennetworking.org, andy@opennetworking.org"
+          maintainers: "onf-bat-admin@opennetworking.org, andy@opennetworking.org"
           docker-repo: 'xosproject'
           dependency-jobs: 'version-tag_wildcard'