Fix get-policy/put-policy invalid entries.

Also update documentation, to use subdomains for buckets as minio
server starts supporting subdomains.

docs/sdks/ruby/example-list-buckets.rb

@@ -1,7 +1,7 @@
 #!/usr/bin/env ruby
 require 'aws-sdk'
 
-s3 = Aws::S3::Client.new(endpoint: "http://127.0.0.1:9000/",
+s3 = Aws::S3::Client.new(endpoint: "http://localhost:9000/",
                          require_https_for_sse_cpk: false,
                          region: "minio")
 resp = s3.list_buckets