Tidy up changeset comment code

db/migrate/20140507110937_create_changeset_comments.rb

@@ -9,8 +9,10 @@ class CreateChangesetComments < ActiveRecord::Migration
       t.timestamp :created_at, :null => false
       t.boolean :visible, :null => false
     end
+
     add_foreign_key :changeset_comments, [:changeset_id], :changesets, [:id]
     add_foreign_key :changeset_comments, [:author_id], :users, [:id]
+
     add_index :changeset_comments, :created_at
   end
 end