Add widget feeds to homepage

Note there is some funkiness going on with class loadings
Had to create a `feed` and `widget_feed` table even though in this
first version the Widget::Feed includes only uses ActiveModel instead
of ActiveRecord, otherwise some specs failed

We’ll figure it out and clean up 😌

db/migrate/20180519132610_create_widget_feeds.rb

@@ -0,0 +1,6 @@
+class CreateWidgetFeeds < ActiveRecord::Migration
+  def change
+    create_table :widget_feeds do |t|
+    end
+  end
+end

db/migrate/20180519132715_create_feeds.rb

@@ -0,0 +1,6 @@
+class CreateFeeds < ActiveRecord::Migration
+  def change
+    create_table :feeds do |t|
+    end
+  end
+end