グカネータ作成 (#041) (#362)

Reviewed-on: #362
Co-authored-by: miteruzo <miteruzo@naver.com>
Co-committed-by: miteruzo <miteruzo@naver.com>

backend/app/models/gekanator_game.rb

@@ -0,0 +1,15 @@
+class GekanatorGame < ApplicationRecord
+  belongs_to :user
+  belongs_to :guessed_post, class_name: 'Post'
+  belongs_to :correct_post, class_name: 'Post'
+  has_many :question_suggestions,
+           class_name: 'GekanatorQuestionSuggestion',
+           dependent: :delete_all
+  has_many :question_examples,
+           class_name: 'GekanatorQuestionExample',
+           dependent: :delete_all
+
+  validates :answers, presence: true
+  validates :question_count, numericality: { greater_than_or_equal_to: 0 }
+  validates :won, inclusion: { in: [true, false] }
+end