migration for quote schema update

db/migrate/20190804115634_add_quote_id_to_statuses.rb

@@ -0,0 +1,7 @@
+class AddQuoteIdToStatuses < ActiveRecord::Migration[5.2]
+  def change
+    safety_assured { 
+        add_reference :statuses, :quote_of, foreign_key: { on_delete: :nullify, to_table: :statuses }
+    }
+  end
+end