code: function scrapeSearchPage(pageUrl) {
  
      return co(function *() {
          //Load the HTML page
          const $ = cheerio.load(yield request(pageUrl));
  
          //For each card, scrape some data
          const cards = Array.from($("#cardResults li")).map(el => {
              const $card = $(el);
  
              //Just scrape the database URL and the image for now
              const url = Url.resolve(SCRAPE_URL, $card.find("a").attr("href"));
              return {
                  url: url,
                  image: Url.resolve(SCRAPE_URL, $card.find("img").attr("src")),
                  id: cardIdFromUrl(url)
              };
          });
  
          //Work out how many pages in total there are
          const totalText = $('#cards-load-more>div>span').text();
          const numPages = parseInt(/\d of (\d+)/.exec(totalText)[1]);
  
          return {
              numPages: numPages,
              cards: cards
          };
  
      })();
  }
docs: Scrapes the page at the given URL, and returns an object {cards, numPages} where cards is an array of card objects
  and numPages is the number of pages returned from this query