Use summary when there isn't a title

Follwing the
[spec](https://validator.w3.org/feed/docs/rss2.html#hrelementsOfLtitemgt)
for RSS, if the title property isn't present for a story, we should
display the description, which is the [summary in
feedjira](https://github.com/feedjira/feedjira/blob/d0a28c3ba6437d70e4ca886ae5c05287bf1b6821/lib/feedjira/parser/itunes_rss_item.rb#L13).

app/repositories/story_repository.rb

@@ -9,7 +9,7 @@ def self.add(entry, feed)
     entry.url = normalize_url(entry.url, feed.url) unless entry.url.nil?
 
     Story.create(feed: feed,
-                 title: sanitize(entry.title),
+                 title: extract_title(entry),
                  permalink: entry.url,
                  body: extract_content(entry),
                  is_read: false,
@@ -95,6 +95,12 @@ def self.extract_content(entry)
     expand_absolute_urls(sanitized_content, entry.url)
   end
 
+  def self.extract_title(entry)
+    return sanitize(entry.title) if entry.title.present?
+    return sanitize(entry.summary) if entry.summary.present?
+    "There isn't a title for this story"
+  end
+
   def self.sanitize(content)
     Loofah.fragment(content.gsub(/<wbr\s*>/i, ""))
           .scrub!(:prune)

spec/repositories/story_repository_spec.rb

@@ -26,6 +26,23 @@
     end
   end
 
+  describe ".extract_title" do
+    let(:entry) do
+    end
+
+    it "returns the title if there is a title" do
+      entry = double(title: "title", summary: "summary")
+
+      expect(StoryRepository.extract_title(entry)).to eq "title"
+    end
+
+    it "returns the summary if there isn't a title" do
+      entry = double(title: "", summary: "summary")
+
+      expect(StoryRepository.extract_title(entry)).to eq "summary"
+    end
+  end
+
   describe ".extract_content" do
     let(:entry) do
       double(url: "http://mdswanson.com",