Fix legislation process feed order

We need to add an ORDER BY clause; not doing so was causing different
processes to show up sometimes. As mentioned in the PostgreSQL manual:

> Because the order of the rows in the database table is unpredictable,
> when you use the LIMIT clause, you should always use the ORDER BY
> clause to control the order of rows. If you don’t do so, you will get
> an unpredictable result set.

app/models/widget/feed.rb

@@ -31,7 +31,7 @@ class Widget::Feed < ActiveRecord::Base
   end
 
   def processes
-    Legislation::Process.open.published.limit(limit)
+    Legislation::Process.open.published.order("created_at DESC").limit(limit)
   end
 
 end