Annotations (#327)

* Add annotate gem to the project
* Annotate models, fixtures, factories and model_specs
* Keep annotations only in Models
* Remove unwanted changes in model specs
* Exclude auto_annotate_models from rubocop

app/models/inbox.rb

@@ -1,5 +1,22 @@
 # frozen_string_literal: true
 
+# == Schema Information
+#
+# Table name: inboxes
+#
+#  id           :integer          not null, primary key
+#  channel_type :string
+#  name         :string           not null
+#  created_at   :datetime         not null
+#  updated_at   :datetime         not null
+#  account_id   :integer          not null
+#  channel_id   :integer          not null
+#
+# Indexes
+#
+#  index_inboxes_on_account_id  (account_id)
+#
+
 class Inbox < ApplicationRecord
   validates :account_id, presence: true