Adds OldNote model file

Adds OldNote model file for modeling one row of old_notes table. Also, added author association for connecting with users table.

app/models/old_note.rb

@@ -0,0 +1,28 @@
+# == Schema Information
+#
+# Table name: old_notes
+#
+#  note_id     :bigint(8)        not null, primary key
+#  latitude    :integer          not null
+#  longitude   :integer          not null
+#  tile        :bigint(8)        not null
+#  timestamp   :datetime         not null
+#  status      :enum             not null
+#  description :text             default(""), not null
+#  user_id     :bigint(8)
+#  user_ip     :inet
+#  version     :bigint(8)        default(1), not null, primary key
+#
+# Indexes
+#
+#  index_old_notes_on_version  (version)
+#
+# Foreign Keys
+#
+#  old_notes_note_id_fkey  (note_id => notes.id)
+#  old_notes_user_id_fkey  (user_id => users.id)
+#
+
+class OldNote < ApplicationRecord
+  belongs_to :author, :class_name => "User", :foreign_key => "user_id", :optional => true
+end