Pushes 16x parallel changes on the CI

During the hackathon in Lund we need to keep-up with
the pace of changes. We have now more GCE nodes to
support up to 16 parallel changes validations in
parallel.

Change-Id: Iffb89c39780ee9cde7fa20838a8f5d1ece20a890
diff --git a/jenkins/gerrit-verifier-flow.groovy b/jenkins/gerrit-verifier-flow.groovy
index 4779d63..608a8f0 100644
--- a/jenkins/gerrit-verifier-flow.groovy
+++ b/jenkins/gerrit-verifier-flow.groovy
@@ -33,7 +33,7 @@
   static int numRetryBuilds = 3
   static int myAccountId = 1022687
   static int waitForResultTimeout = 10000
-  static int maxBuilds = 4
+  static int maxBuilds = 16
   static String verifierJobName = "Gerrit-verifier-change"
 }