title: NSAttributed String Won't change font
body: <p>I'm trying to format the placeholder text of a <code>UITextField</code> using an <code>NSAttributedString</code>. This code works successfully for the foreground color and kerning attributes. However, it won't change the font or the font size. What am I doing wrong? Thanks!</p>
  
  <pre><code>NSAttributedString *aString = [[NSAttributedString alloc] initWithString:
                                    @"USER NAME"
                                    attributes:@{
                                                NSForegroundColorAttributeName: [UIColor redColor],
                                                NSFontAttributeName : [UIFont fontWithName:@"Georgia" size:8.0f],
                                                NSKernAttributeName : [NSNumber numberWithFloat:3.0f]
                                                                                                      }];
  self.userNameTextField.attributedPlaceholder = [aString copy];
  </code></pre>