title: Dropbox image uploads results authentication error
body: <p>I am developing an iphone application which uploads an image to dropbox. I used the following code for image uploading.</p>
  
  <pre><code>NSData *datobj = UIImagePNGRepresentation(pic.image);
      NSString *stringConvertion = [[NSString alloc] initWithData:datobj encoding:NSUTF8StringEncoding];
      NSString *filename = stringConvertion;
      NSString *tmpPngFile = [NSTemporaryDirectory() stringByAppendingPathComponent:@"Temp.png"];
      [UIImagePNGRepresentation(pic.image) writeToFile:tmpPngFile atomically:NO];
      NSString *destDir = @"/";
      [[self restClient] uploadFile:filename toPath:destDir
                      withParentRev:nil fromPath:tmpPngFile];
  </code></pre>
  
  <p>But i am getting an error as follows
  error making request to /1/files_put/dropbox - Authentication failed
  How can I make authentication ?</p>