title: xml-js package converting xml string (not file) to js scrambles utf-8 charcaters
body: <p>Using npm package <code>xml-js</code> I tried to convert some xml string with <code>utf-8</code> characters in it. The method <code>xml2js(..)</code> is used. It scrmabled utf-8 characters like german umlaut chracters. Please take a look at the bellow example and consequent result:</p>
  
  <pre><code>var convert = require('xml-js');
  var xml =
  '&lt;?xml version="1.0" encoding="utf-8"?&gt;' +
  '&lt;note importance="high" logged="true"&gt;' +
  '    &lt;title&gt;Deutsche TODOs&lt;/title&gt;' +
  '    &lt;todo&gt;Ihr seid schön!&lt;/todo&gt;' +
  '    &lt;todo&gt;Schönen abend sagen zur meine Frau!&lt;/todo&gt;' +
  '&lt;/note&gt;';
  var result1 = convert.xml2json(xml, {compact: true, spaces: 4});
  console.log(result1, '\n', result1);
  </code></pre>
  
  <p><strong>Result1</strong>
  It simply scrambles the text with umlauts inside the <code>&lt;todo&gt;</code> tags:</p>
  
  <pre><code> {
      "_declaration": {
          "_attributes": {
              "version": "1.0",
              "encoding": "utf-8"
          }
      },
      "note": {
          "_attributes": {
              "importance": "high",
              "logged": "true"
          },
          "title": {
              "_text": "Deutsche TODOs"
          },
          "todo": [
              {
                  "_text": "Ihr seid schÃ¶n!"
              },
              {
                  "_text": "SchÃ¶nen abend sagen zur meine Frau!"
              }
          ]
      }
  }
  </code></pre>
  
  <p><strong>EDIT: The original text that I was running into trouble with has been given in the link below in the <code>runkit</code> link:</strong></p>
  
  <p><a href="https://runkit.com/cfmes/5d1cb38d0d5e21001b5d4677" rel="nofollow noreferrer">https://runkit.com/cfmes/5d1cb38d0d5e21001b5d4677</a></p>
  
  <p>The problem is it's not reproduceable in the <code>runkit</code> app but in my app on the powershell console, the scrambledtext is showing all the time even though I have updated from version <code>xml-js@1.6.8</code> to <code>xml-js@1.6.11</code>.</p>
  
  <p>Got any solution for this?</p>
  
  <p>Regards
  Emdadul</p>