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/conversation.rb

@@ -1,3 +1,27 @@
+# == Schema Information
+#
+# Table name: conversations
+#
+#  id                    :integer          not null, primary key
+#  additional_attributes :jsonb
+#  agent_last_seen_at    :datetime
+#  locked                :boolean          default(FALSE)
+#  status                :integer          default("open"), not null
+#  user_last_seen_at     :datetime
+#  created_at            :datetime         not null
+#  updated_at            :datetime         not null
+#  account_id            :integer          not null
+#  assignee_id           :integer
+#  contact_id            :bigint
+#  display_id            :integer          not null
+#  inbox_id              :integer          not null
+#
+# Indexes
+#
+#  index_conversations_on_account_id                 (account_id)
+#  index_conversations_on_account_id_and_display_id  (account_id,display_id) UNIQUE
+#
+
 class Conversation < ApplicationRecord
   include Events::Types