title: Capture and assert Meta tags in RSpec
body: <p>I am trying to write a unit test to assert few meta tag values (under  section of the response). How can I use the attribute tag to check individual value?
  Ex:</p>
  
  <pre><code>&lt;meta property="keyword" content="site keywords" /&gt;
  &lt;meta property="description" content="site description" /&gt;
  </code></pre>
  
  <p>So far this is all I got. But it comes back as failed.</p>
  
  <pre><code>it "should check meta fields" do
    get :show, {:format =&gt; 'html' }
    r = response.body
    r.should have_selector('meta', :content =&gt; @site.title)
  end
  </code></pre>