title: R markdown doesn't knit author name in pdf
body: <p>I am writing a document in r markdown. When I knit it to pdf, instead of the author name the pdf simply displays "true.</p>
  
  <p>The knitting works perfectly well with html outputs, besides it seems to me it should work.</p>
  
  <pre class="lang-r prettyprint-override"><code>---
  title: "knitr will you work please?"
  author:
    name: John Smith
  output: pdf_document
  ---
  </code></pre>
  
  <p>The output will display </p>
  
  <pre><code>knitr will you work please?
  true
  </code></pre>
  
  <p>and not</p>
  
  <pre><code>knitr will you work please?
  John Smith
  </code></pre>