Add Gerrit-CI validation

Change-Id: I53190919ab7ab72c6d5a9143b226da2f0a4b434b

Jenkinsfile

diff --git a/Jenkinsfile b/Jenkinsfile
new file mode 100644
index 0000000..981c2bb
--- /dev/null
+++ b/Jenkinsfile
@@ -0,0 +1,2 @@
+pluginPipeline(formatCheckId: 'gerritforge:plugins-events-gcloud-pubsub-code-style',
+                buildCheckId: 'gerritforge:plugins-events-gcloud-pubsub-build-test')