Fix issues where cryptsetup would fail to unmount

There were occasions where removing the backup drive would confuse luks
and prevent re-mounting. This fixes the issue by attempting to luks
close and open the drive before mounting, thereby correcting any issues
where the drive would stick.

ansible/arch_backup/vars/main.yml

@@ -2,6 +2,9 @@
 mount:
   path: /mnt/backup0
 
+snapshots:
+  path: /.snapshots
+
 disk:
   name: backup0
   uuid: 1d7ce570-e695-47a0-9dda-5f14b5b20e21
@@ -10,3 +13,8 @@ disk:
 backups:
   - /
   - /home
+
+notifications:
+  user:
+    name: ducoterra
+    uid: 1000