Feature/scraper

Scraper works
what this was for, probably in something that didn't get commited is to memoize the method. So it should be

```ruby
# this also has changes you mentioned below
@images = slides.css('img')
                     .compact # I actually don't know if this responds to compact
                     .map { |img| "%s%s" % [@base_url, img['src']] }
```
I would probably explicitly return @images here also. Just to be obvious even though it isn't necessary.