title: What are all the font weights available for google fonts?
body: <p>For example I could do an import like this:</p>
  
  <pre><code>@import url(http://fonts.googleapis.com/css?family=Roboto:100,400,900);
  </code></pre>
  
  <p>But could I also do one like this and would it make sense (Are the only valid values 100, 400, 900)?</p>
  
  <pre><code>@import url(http://fonts.googleapis.com/css?family=Roboto:100,200, 300, 400,500, 600, 700, 800, 900);
  </code></pre>