Add job to build jnlp-slave docker images

Change-Id: I08ab3a0b90a72496fcf729a4fa25b4a838370835
diff --git a/jenkins/client/job/docker/init.yml b/jenkins/client/job/docker/init.yml
index b6bab31..b6ed029 100644
--- a/jenkins/client/job/docker/init.yml
+++ b/jenkins/client/job/docker/init.yml
@@ -38,6 +38,10 @@
               branch: "master"
               tags: "5.6 latest"
               dockerfile: "5.6/Dockerfile"
+            - name: jnlp-slave
+              branch: "master"
+              tags: "latest"
+              dockerfile: "Dockerfile"
           template:
             discard:
               build: