Add token string attribute to Poll Answer

app/models/poll/answer.rb

@@ -8,6 +8,7 @@ class Poll::Answer < ActiveRecord::Base
   validates :question, presence: true
   validates :author, presence: true
   validates :answer, presence: true
+  validates :token, presence: true
 
   # temporary skipping validation, review when removing valid_answers
   # validates :answer, inclusion: { in: ->(a) { a.question.valid_answers }},
@@ -19,4 +20,4 @@ class Poll::Answer < ActiveRecord::Base
   def record_voter_participation
     Poll::Voter.find_or_create_by!(user: author, poll: poll, origin: "web")
   end
-end
+end