title: YII2 DOC-2.0: RESTFUL POST example return invalid json
body: <p>When I use command in <a href="http://www.yiiframework.com/doc-2.0/guide-rest-quick-start.html" rel="nofollow">http://www.yiiframework.com/doc-2.0/guide-rest-quick-start.html</a>:</p>
  
  <pre><code>curl -i -H "Accept:application/json" -H "Content-Type:application/json" -XPOST   "my api path/users" -d '{"username": "testuser", "email": "user@123.com"}'
  </code></pre>
  
  <p>it returns:</p>
  
  <pre><code>HTTP/1.1 400 Bad Request
  Date: Tue, 01 Mar 2016 06:51:03 GMT
  Server: Apache/2.4.4 (Win32) PHP/5.6.9
  X-Powered-By: PHP/5.6.9
  Vary: Accept-Encoding
  Content-Length: 148
  Connection: close
  Content-Type: application/json; charset=UTF-8
  
  {"name":"Bad Request","message":"Invalid JSON data in request body: Syntax error
  .","code":0,"status":400,"type":"yii\\web\\BadRequestHttpException"}curl: (6) Co
  uld not resolve host: testuser,
  curl: (6) Could not resolve host: email
  curl: (3) [globbing] unmatched close brace/bracket at pos 13
  </code></pre>