Run Chef again after upgrading centaurus to Ubuntu 20.04

Closes #195

nodes/centaurus.kosmos.org.json

@@ -8,11 +8,12 @@
   "automatic": {
     "fqdn": "centaurus.kosmos.org",
     "os": "linux",
-    "os_version": "4.15.0-101-generic",
+    "os_version": "5.4.0-42-generic",
     "hostname": "centaurus",
     "ipaddress": "78.46.59.98",
     "roles": [
       "gitea",
+      "postgresql_client",
       "postgresql_replica"
     ],
     "recipes": [
@@ -30,6 +31,7 @@
       "ntp::default",
       "ntp::apparmor",
       "kosmos-base::systemd_emails",
+      "apt::unattended-upgrades",
       "kosmos-base::firewall",
       "kosmos-postfix::default",
       "postfix::default",
@@ -54,7 +56,7 @@
       "build-essential::default"
     ],
     "platform": "ubuntu",
-    "platform_version": "18.04",
+    "platform_version": "20.04",
     "cloud": null,
     "chef_packages": {
       "ohai": {