Offline participation: implement completed puzzle methods

spec/factories/offlines.rb

@@ -3,6 +3,7 @@
 # Table name: offlines
 #
 #  id         :integer          not null, primary key
+#  completed  :boolean
 #  end_time   :datetime
 #  name       :string           not null
 #  start_time :datetime         not null
@@ -20,6 +21,6 @@
 #
 FactoryBot.define do
   factory :offline do
-    
+    name { "test" }
   end
 end