title: Angular 2 - Unexpected token < in JSON at position 0
body: <p>i'am trying to make a post request to my RESTful api on Laravel 5.2. But in the console appear this: </p>
  
  <blockquote>
    <p>"Unexpected token &lt; in JSON at position 0"</p>
  </blockquote>
  
  <p>Here is the code:</p>
  
  <pre><code>private post(post: Post): Promise&lt;Post&gt; {
      let headers = new Headers({
    'Content-Type': 'application/json'});
      return this.http
                 .post(this.url+'courses', JSON.stringify(post ||  null), {headers: headers})
                 .toPromise()
                 .then(res =&gt; res.json().data)
                 .catch(this.handleError);
  }
  </code></pre>
  
  <p>Someone can help me? Thanks.</p>