Add validation dependency on events-broker module

Clone and build events-broker from source when validating
changes on events-kafka.

Change-Id: I5d452dd80258070454936f6f18ac8fcd754c2125
diff --git a/Jenkinsfile b/Jenkinsfile
index b26b19f..589453c 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -1,2 +1,3 @@
 pluginPipeline(formatCheckId: 'gerritforge:plugins-events-kafka-code-style',
-                buildCheckId: 'gerritforge:plugins-events-kafka-build-test')
+                buildCheckId: 'gerritforge:plugins-events-kafka-build-test',
+                extraModules: ['events-broker'])