Add migration to delete the image and styles from banners, in order to use background_color and font_color

db/migrate/20180124143013_remove_image_and_style_from_banners.rb

@@ -0,0 +1,6 @@
+class RemoveImageAndStyleFromBanners < ActiveRecord::Migration
+  def change
+    remove_column :banners, :image
+    remove_column :banners, :style
+  end
+end

db/schema.rb

@@ -67,8 +67,6 @@ ActiveRecord::Schema.define(version: 20180519132610) do
     t.string   "title",           limit: 80
     t.string   "description"
     t.string   "target_url"
-    t.string   "style"
-    t.string   "image"
     t.date     "post_started_at"
     t.date     "post_ended_at"
     t.datetime "hidden_at"