Validate high-availability plugin using Gerrit CI

The Gerrit CI pipeline includes both Java 8 and Java 11
JVMs and is able to validate the changes on master and
as well on all other branches.

Change-Id: I9cb2b78e435ef82e0b264bee146adf37b7a07253

Jenkinsfile

diff --git a/Jenkinsfile b/Jenkinsfile
new file mode 100644
index 0000000..0c516ca
--- /dev/null
+++ b/Jenkinsfile
@@ -0,0 +1,2 @@
+pluginPipeline(formatCheckId: 'gerritforge:plugins-high-availability-code-style',
+               buildCheckId: 'gerritforge:plugins-high-availability-build-test')