CI test with cron install for TU

.gitlab-ci.yml

@@ -12,6 +12,7 @@ stages:
 before_script:
   - apt-get update > /dev/null
   - apt-get install apt-utils -yqq > /dev/null
+  - apt-get install cron -yqq > /dev/null
   - apt-get install tar -yqq > /dev/null
   - apt-get install wkhtmltopdf -yqq > /dev/null
   - apt-get install wget -yqq > /dev/null