[copr] enable redis for backend

roles/copr/backend/tasks/main.yml

@@ -10,6 +10,9 @@
   - python-novaclient
   - obs-signd # TODO: remove, since it will be installed as dependency by copr-backend
 
+- name: enable and start redis  # TODO: .service in copr-backend should depend on redis
+  service: name=redis enabled=yes state=started
+
 - name: make copr dirs
   file: state=directory path={{ item }}
   with_items: