fix timestamps on feedback (and fix deployment)

config/deploy.rb

@@ -15,7 +15,7 @@ namespace :deploy do
   after :compile_assets, :copy_vendor_assets do
     on roles(fetch(:assets_roles)) do
       within release_path do
-        execute :cp, 'vendor/assets/images/*', 'public/assets/'
+        execute :cp, '-r', 'vendor/assets/images/', 'public/assets/'
         execute :cp, '-r', 'vendor/assets/javascripts/ace', 'public/assets/'
       end
     end

db/migrate/20180222145909_fix_timestamps_on_feedback.rb

@@ -0,0 +1,6 @@
+class FixTimestampsOnFeedback < ActiveRecord::Migration
+  def change
+    change_column_default(:user_exercise_feedbacks, :created_at, nil)
+    change_column_default(:user_exercise_feedbacks, :updated_at, nil)
+  end
+end