refactor: update repo and install packages in one step

tasks/install-packages.yml

 ---
-- name: apt-get update
-  apt:
-    update_cache: "yes"
-  tags: [apt]
-
 - name: install packages (rsync, sarg, squid3, tar, unzip)
   apt:
     state: present
@@ -14,4 +9,5 @@
       'tar',
       'unzip'
     ]
+    update_cache: "yes"
   tags: [apt]