title: bookdown encoding set to LATIN1 instead of UTF-8
body: <p>Why when i build a book using <code>build book</code> button it sets my encoding to <code>LATIN1</code> instead of <code>UTF-8</code>?
  Also, whenever i open a chapter (.Rmd file) i've got reopen it with UTF-8 encoding 'cause it changes back do LATIN1 even if i have just saved it in UTF-8.</p>
  
  <pre><code>==&gt; rmarkdown::render_site(output_format = 'bookdown::gitbook', encoding = 'LATIN1')
  </code></pre>