Remove deprecated attributes from Poll:Question

Some fields from Poll::Question are translatable and we no longer need
them. This commit will remove the annoying deprecation warning thrown
by Globalize gem after gem version update.

db/migrate/20190221162858_remove_deprecated_translatable_fields_from_poll_questions.rb

@@ -0,0 +1,5 @@
+class RemoveDeprecatedTranslatableFieldsFromPollQuestions < ActiveRecord::Migration[4.2]
+  def change
+    remove_column :poll_questions, :title, :string
+  end
+end

db/schema.rb

@@ -1172,7 +1172,6 @@ ActiveRecord::Schema.define(version: 20190607160900) do
     t.integer  "poll_id"
     t.integer  "author_id"
     t.string   "author_visible_name"
-    t.string   "title"
     t.integer  "comments_count"
     t.datetime "hidden_at"
     t.datetime "created_at"