migration and associations

completes #26

db/migrate/20160915164450_create_reviewer_to_quizzes.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+class CreateReviewerToQuizzes < ActiveRecord::Migration[5.0]
+  def change
+    create_table :reviewer_to_quizzes do |t|
+      t.integer :user_id, null: false
+      t.integer :quiz_id, null: false
+
+      t.timestamps
+    end
+    add_index :reviewer_to_quizzes, :quiz_id
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20160826200610) do
+ActiveRecord::Schema.define(version: 20160915164450) do
 
   create_table "answers", force: :cascade, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8" do |t|
     t.integer  "candidate_id"
@@ -65,6 +65,14 @@ ActiveRecord::Schema.define(version: 20160826200610) do
     t.string   "name"
   end
 
+  create_table "reviewer_to_quizzes", force: :cascade, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8" do |t|
+    t.integer  "user_id",    null: false
+    t.integer  "quiz_id",    null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["quiz_id"], name: "index_reviewer_to_quizzes_on_quiz_id", using: :btree
+  end
+
   create_table "users", force: :cascade, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8" do |t|
     t.string   "name"
     t.string   "email"