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/swap.yml

@@ -0,0 +1,15 @@
+- block:
+  - name: server | system setup | create swapfile
+    command: "fallocate -l {{ ansible_facts['memtotal_mb'] / 4 | round }} /swapfile"
+  - name: server | system setup | format swapfile
+    filesystem:
+      fstype: swap
+      dev: "/swapfile" # required. Target path to device or image file.
+  - name: server | system setup | enable swap
+    command: "swapon /swapfile"
+  - name: server | system setup | edit fstab
+    lineinfile:
+      path: "/etc/fstab"
+      state: present
+      line: "/swapfile none swap sw 0 0"
+  when: ansible_facts['memory_mb']['swap']['total'] == '0'