title: rake test and error : log writing failed. "\xE2" from ASCII-8BIT to UTF-8
body: <p>When I run <code>rake test</code>, I get error line every time.</p>
  
  <pre><code>log writing failed. "\xE2" from ASCII-8BIT to UTF-8  
  </code></pre>
  
  <p>Please guide on this. How to remove this error.</p>