Map /var/lib/jenkins as volume for jenkins slaves

Change-Id: I60ea1c34a775835c086504e4e8347151d45888fa
diff --git a/docker/swarm/stack/jenkins/slave.yml b/docker/swarm/stack/jenkins/slave.yml
index 52015ec..fc281b7 100644
--- a/docker/swarm/stack/jenkins/slave.yml
+++ b/docker/swarm/stack/jenkins/slave.yml
@@ -31,6 +31,7 @@
                 - /etc/aptly-publisher.yaml:/etc/aptly-publisher.yaml:ro
                 - /var/run/docker.sock:/var/run/docker.sock
                 - /usr/bin/docker:/usr/bin/docker:ro
+                - /var/lib/jenkins:/var/lib/jenkins
             slave02:
               environment:
                 JENKINS_URL: ${_param:jenkins_master_url}
@@ -50,6 +51,7 @@
                 - /etc/aptly-publisher.yaml:/etc/aptly-publisher.yaml:ro
                 - /var/run/docker.sock:/var/run/docker.sock
                 - /usr/bin/docker:/usr/bin/docker:ro
+                - /var/lib/jenkins:/var/lib/jenkins
             slave03:
               environment:
                 JENKINS_URL: ${_param:jenkins_master_url}
@@ -69,3 +71,4 @@
                 - /etc/aptly-publisher.yaml:/etc/aptly-publisher.yaml:ro
                 - /var/run/docker.sock:/var/run/docker.sock
                 - /usr/bin/docker:/usr/bin/docker:ro
+                - /var/lib/jenkins:/var/lib/jenkins