title: After upgrading Rails from 5.1 to 5.2 I got following warning messages
body: <p>After upgrading Rails from 5.1 to 5.2 I got the following warning messages.</p>
  
  <pre><code>[fog][DEPRECATION] Unable to load Fog::AWS::CDN
  [fog][DEPRECATION] The format Fog::CDN::AWS is deprecated
  [fog][DEPRECATION] Unable to load Fog::AWS::Compute
  [fog][DEPRECATION] The format Fog::Compute::AWS is deprecated
  [fog][DEPRECATION] Unable to load Fog::AWS::DNS
  [fog][DEPRECATION] The format Fog::DNS::AWS is deprecated
  [fog][DEPRECATION] Unable to load Fog::AWS::Storage
  [fog][DEPRECATION] The format Fog::Storage::AWS is deprecated
  </code></pre>
  
  <p>Gemfile</p>
  
  <pre><code>gem 'rails', '~&gt; 5.2'
  gem 'aws-sdk', '~&gt; 2'
  gem 'fog-aws'
  </code></pre>
  
  <p>How can I fix this?</p>