Add travis tests

roles/kubernetes/preinstall/tasks/main.yml

@@ -1,7 +1,8 @@
 ---
 - name: "Identify init system"
   shell: >
-    if $(pgrep systemd > /dev/null); then
+    $(pgrep systemd > /dev/null && systemctl status > /dev/null);
+    if [ $? -eq 0 ] ; then
       echo systemd;
     else
       echo sysvinit;