Add number of pieces to puzzles

app/models/puzzle.rb

@@ -5,6 +5,7 @@
 #  id         :integer          not null, primary key
 #  brand      :string
 #  name       :string
+#  pieces     :integer          not null
 #  created_at :datetime         not null
 #  updated_at :datetime         not null
 #  contest_id :integer          not null
@@ -24,4 +25,5 @@ class Puzzle < ApplicationRecord
   has_one_attached :image
 
   validates :name, presence: true
+  validates :pieces, presence: true
 end