title: Regex for capital letters not matching accented characters
body: <p>I am new to ruby and I'm trying to work with regex.</p>
  
  <p>I have a text which looks something like:</p>
  
  <pre><code>HEADING
  
  Some text which is always non capitalized. Headings are always capitalized,     followed by a space or nothing more.
  
  YOU CAN HAVE MULTIPLE WORDS IN HEADING
  </code></pre>
  
  <p>I'm using this regular expression to choose all headings:</p>
  
  <pre><code>^[A-Z]{2,}\s?([A-Z]{2,}\s?)*$
  </code></pre>
  
  <p>However, it matches all headings which does not contain chars as Č, Š, Ž(slovenian characters).</p>
  
  <p>So I'm guessing [A-Z] only matches ASCII characters? How could I get utf8?</p>