title: AWS Cloudformation error: Template format error: Invalid outputs property : [Ref]
body: <p>I'm trying to use this template:</p>
  <p><a href="https://gist.github.com/jbt/712d1abdf40db84ea5e24d8c5d0db712" rel="nofollow noreferrer">https://gist.github.com/jbt/712d1abdf40db84ea5e24d8c5d0db712</a></p>
  <p>found here:</p>
  <p><a href="https://www.gosquared.com/blog/simple-high-availability-wordpress-hosting-on-aws" rel="nofollow noreferrer">https://www.gosquared.com/blog/simple-high-availability-wordpress-hosting-on-aws</a></p>
  <p>But I receive the error in the object:</p>
  <blockquote>
  <p>Template format error: Invalid outputs property : [Ref].</p>
  </blockquote>
  <p>If I open the designer and try to validate the template in JSON format I received this error.</p>
  <blockquote>
  <p>Template contains errors.: Template error: every Fn::GetAtt object requires two non-empty parameters, the resource name and the resource attribute</p>
  </blockquote>
  <p>I'm quite new in yaml template so I don't know exactly which could be the problem.</p>
  <p>Any suggestion?</p>