title: How to properly handle text/plain responses with retrofit?
body: <p>I have a webservice call which response is plain text and no json. In the callback below, failure() always gets called even with successful responses because retrofit tries to parse the response as json.</p>
  
  <pre><code>new Callback&lt;String&gt;() {
          @Override
          public void success(String s, Response response) {
          ...    
          }
  
          @Override
          public void failure(RetrofitError error) {
          ...
          }
      });
  </code></pre>
  
  <p>The following error occurs:</p>
  
  <blockquote>
    <p>retrofit.RetrofitError: com.google.gson.JsonSyntaxException: com.google.gson.stream.MalformedJsonException: Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 16 path $</p>
  </blockquote>
  
  <p>How can I tell retrofit, that the response is plain text and should not be treated as json?</p>