swap and sysctl tasks added

if swap not enabled, enable swap
set vm.swappiness and vm.vfs_cache_pressure on servers

roles/server/tasks/system_setup/sysctl.yml

@@ -0,0 +1,9 @@
+- name: server | system setup | sysctl
+  sysctl:
+    name: "{{ item.key }}"
+    value: "{{ item.value }}"
+    state: present
+    reload: yes
+  loop:
+    - { key: "vm.swappiness", value: "10"}
+    - { key: "vm.vfs_cache_pressure", value: "50"}