Execute flows concurrently

Allow build flows to run concurrently to fill any
potential bandwidth gaps with outstanding changes
to be built.

Change-Id: Iaf5868b252ceea921a5f272055f01a6b2f384071
diff --git a/jenkins/gerrit-verifier.yaml b/jenkins/gerrit-verifier.yaml
index b3efd79..cdc76c5 100644
--- a/jenkins/gerrit-verifier.yaml
+++ b/jenkins/gerrit-verifier.yaml
@@ -145,9 +145,10 @@
 
 - job:
     name: 'Gerrit-verifier-flow'
+    concurrent: true
     project-type: flow
     triggers:
-      - timed: 'H/10 * * * *'
+      - timed: 'H/5 * * * *'
     logrotate:
       numToKeep: 20
     dsl: