title: upgrade sass-rails gem to 5.0 gives deprecation warning
body: <p>We upgraded to sass-rails version 5.0.0 and are getting this deprecation warning:</p>
  
  <pre><code>DEPRECATION WARNING: Extra .css in SCSS file is unnecessary. Rename /Users/foo/Projects/foo/app/assets/stylesheets/foo.css.scss to /Users/foo/Projects/foo/app/assets/stylesheets/foo.scss. (called from _app_views_layouts_application_html_erb__1560597815210891605_70190441246060 at /Users/foo/Projects/foo/app/views/layouts/application.html.erb:13)
  </code></pre>
  
  <p>Anyone know whats going on with this?  Does the gem really want me to rename all of my stylesheet assets from:</p>
  
  <pre><code>app/assets/stylesheets/foo.css.scss
  </code></pre>
  
  <p>to:</p>
  
  <pre><code>app/assets/stylesheets/foo.scss
  </code></pre>
  
  <p>?</p>
  
  <p>Seems to run against years of Rails convention to me.  Perhaps there is a way to suppress the deprecation warning?   </p>