title: Elixir convert encoding EUC-KR(JP, CH)... to UTF-8
body: <p>I'm making crawling app. I want to parse some characters.
  But some pages are not UTF-8 charset.</p>
  
  <p>I got page body and now I want to do some work with the body string. 
  First of all, I should convert encoding to UTF-8 if the page encoding is not UTF-8.</p>
  
  <p>How can I do?</p>