feat: add cronExpression param

Related to: #1



Signed-off-by: sebastien.heurtematte <sebastien.heurtematte@eclipse-foundation.org>

Jenkinsfile

@@ -3,6 +3,7 @@
 hugo (
   appName: 'webdev.eclipse.org-spec-host',
   productionDomain: 'webdev.eclipse.org',
+  cronExpression: 'H H * * *',
   build: [
     script: 'fetch.sh'
   ],