annotate models (#2697)

* add annotate to Gemfile

* rails g annotate:install

* configure annotate_models

* add schema info to models

* fix rubocop to add frozen_string_literal

app/models/tag.rb

@@ -1,4 +1,13 @@
 # frozen_string_literal: true
+# == Schema Information
+#
+# Table name: tags
+#
+#  id         :integer          not null, primary key
+#  name       :string           default(""), not null
+#  created_at :datetime         not null
+#  updated_at :datetime         not null
+#
 
 class Tag < ApplicationRecord
   has_and_belongs_to_many :statuses