allow access to backups through sftp in ro mode

roles/common/molecule/default/group_vars/all.yml

@@ -0,0 +1,17 @@
+borgmatic_config:
+  location:
+    source_directories:
+      - /home
+      - /root
+    repositories:
+      - "{{ borg_repository }}"
+    exclude_caches: true
+  storage:
+    umask: "{{ borg_umask }}"
+    encryption_passphrase: "{{ vault_borg_passphrase }}"
+    compression: zlib,7
+  retention:
+    keep_hourly: 24
+    keep_daily: 7
+    keep_weekly: 4
+    keep_monthly: 6