burp-server: Deploy MinIO

We're going to run MinIO on the BURP server to provide a backup target
for the [Postgres Operator][0]/[WAL-E][1].  Although the Postgres
Operator also supports backups via [WAL-G][2], which supports more
backup targets like SFTP, the operator does not support restoring from
those targets.  As such, the best way to get fully-featured backups for
the Postgres Operator, including environment cloning, etc., is to use
S3.  Since I absolutely do not want to store my backups "in the cloud,"
using MinIO seems a decent alternative.  Running it on the BURP server
allows the backups to be stored and rotated along with regular system
backups.

[0]: https://github.com/zalando/postgres-operator/
[1]: https://github.com/wal-e/wal-e
[2]: https://github.com/wal-g/wal-g

host_vars/burp1.pyrocufflink.blue.yml

@@ -6,3 +6,5 @@ collectd_plugins:
 # its domain permissive until the problems are identified and resolved
 # upstream.
 collectd_selinux_permissive: true
+
+minio_storage_path: /srv/minio