fix errors in migration scripts

kontor-rails/app/controllers/publisher_controller.rb

@@ -0,0 +1,4 @@
+class PublisherController < ApplicationController
+  def index
+  end
+end

kontor-rails/app/helpers/publisher_helper.rb

@@ -0,0 +1,2 @@
+module PublisherHelper
+end

kontor-rails/app/models/publisher.rb

@@ -1,3 +1,4 @@
 class Publisher < ApplicationRecord
+  has_many :imprints, class_name: "Publisher", foreign_key: "parent_publisher_id"
   has_many :comics
 end

kontor-rails/app/views/publisher/index.html.erb

@@ -0,0 +1,2 @@
+<h1>Publisher#index</h1>
+<p>Find me in app/views/publisher/index.html.erb</p>