title: How to mock aws-sdk gem to store s3 uploads, sqs messages, sns messages
body: <p>Is there a way to mock s3 bucket, sqs queues, and sns topics in the Ruby aws-sdk (similar to Moto in the Python sdk) to where assertions can be made on those uploaded objects and sent messages after the application code is run?</p>
  <p>I know I am able to stub the response of the aws sdk so that no real requests are sent using the following code:</p>
  <p><code>Aws.config[:stub_responses] = true</code></p>
  <p>But that doesn't get me the ability to make assertions on uploaded s3 objects and sent sqs/sns messages.</p>