Kill trailing whitespace in ruby files

app/logical/post_sets/base.rb

@@ -3,38 +3,38 @@ module PostSets
     def has_wiki?
       false
     end
-    
+
     def wiki_page
       nil
     end
-    
+
     def has_artist?
       false
     end
-    
+
     def artist
       nil
     end
-    
+
     def is_single_tag?
       false
     end
-    
+
     def presenter
       raise NotImplementedError
     end
-    
+
     def arbitrary_sql_order_clause(ids, table_name)
       if ids.empty?
         return "#{table_name}.id desc"
       end
-      
+
       conditions = []
-      
+
       ids.each_with_index do |x, n|
         conditions << "when #{x} then #{n}"
       end
-      
+
       "case #{table_name}.id " + conditions.join(" ") + " end"
     end
   end