Rename subscription#type to subscription_type to avoid rails stumbling over polymorphism

db/migrate/20170913054203_rename_subscription_type.rb

@@ -0,0 +1,5 @@
+class RenameSubscriptionType < ActiveRecord::Migration
+  def change
+    rename_column :subscriptions, :type, :subscription_type
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20170906124500) do
+ActiveRecord::Schema.define(version: 20170913054203) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -325,7 +325,7 @@ ActiveRecord::Schema.define(version: 20170906124500) do
     t.integer  "user_id"
     t.string   "user_type"
     t.integer  "request_for_comment_id"
-    t.string   "type"
+    t.string   "subscription_type"
     t.datetime "created_at",             null: false
     t.datetime "updated_at",             null: false
   end