migration and associations

completes #26

app/models/quiz.rb

@@ -2,6 +2,8 @@
 class Quiz < ApplicationRecord
   has_many :questions, -> { order(:sort) }
   has_many :candidates
+  has_many :reviewer_to_quizzes
+  has_many :reviewers, through: :reviewer_to_quizzes, source: :user
 
   validates :name, presence: true, uniqueness: true
   validates :dept, presence: true

app/models/reviewer_to_quiz.rb

@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+class ReviewerToQuiz < ApplicationRecord
+  belongs_to :user
+  belongs_to :quiz
+end

app/models/user.rb

@@ -1,7 +1,9 @@
 # frozen_string_literal: true
 class User < ApplicationRecord
   has_secure_password
-  has_many :candidates, foreign_key: "recruiter_id"
+  has_many :candidates, foreign_key: :recruiter_id
+  has_many :reviewer_to_quizzes
+  has_many :quizzes, through: :reviewer_to_quizzes
 
   validates :email, presence: true, uniqueness: true
   validates :name, presence: true