title: get responseObject on failure block AFNetworking 3.0
body: <p>how can I get the response string from failure block in AFNetworking 3.x,</p>
  
  <p>In the 2.x version the way to do it was:</p>
  
  <pre><code>[manager GET:path parameters:parameters success:^(AFHTTPRequestOperation *operation, id responseObject) {
      NSDictionary *dictionary_FetchResult = responseObject;
  } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
      NSDictionary *dictionary_FetchResult = operation.responseObject;
  }];
  </code></pre>
  
  <p>but in the 3.x version there is no operation in the returning block's parameter as shown below:</p>
  
  <pre><code>[manager POST:path parameters:parameters progress:^(NSProgress * _Nonnull uploadProgress) {
          } success:^(NSURLSessionDataTask * _Nonnull task, id  _Nullable responseObject) {
      NSDictionary *dictionary_FetchResult = responseObject;
  } failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {
      NSLog(@"Error: %@", error);
  }];
  </code></pre>
  
  <p>so I was hoping if someone was able to achieve that.</p>