Not Capturing Screenshot when using `within`

capybara-screenshot will take screenshot if no element found using find.

``` ruby
find('something that does not exist').click
```

But if no element found using `within`, it does not take any screenshot.

``` ruby
  within('something that does not exist') do
    # do something
  end
```

From my Gemfile.lock, i am using latest version of Capybara, 1.0.11. I am using latest RSpec version, 3.4.
