add build for rpm package

.gitlab-ci.yml

@@ -13,6 +13,13 @@ build-deb-packages:
     artifacts:
         paths:
             - fess.deb
+build-rpm-packages:
+    image: okteto/maven:3
+    stage: build-package
+    script:
+        - mvn antrun:run
+        - mvn package
+        - mvn rpm:rpm
 
 build-docker:
   # Use the official docker image.