title: password regex - raw brace is not allowed in regular expression with unicode flag
body: <p>I am using a jquery plugin bootstrap validator for real-time frontend validations.</p>
  
  <p>When I add a pattern/regex validation to validate a password (any string at least 8 characters long), I get the following error</p>
  
  <blockquote>
    <p>Unable to check <code>&lt;input pattern='^.*{8,}$'&gt;</code> because the pattern is not a valid regexp: raw brace is not allowed in regular expression with unicode flag</p>
  </blockquote>
  
  <p>The Html is</p>
  
  <pre><code>&lt;input pattern="^.*{8,}$" class="form-control" required="required" name="user[password]" id="user_password" type="password"&gt;
  </code></pre>
  
  <p>How should I write the regex ?</p>