Imrpove migrations

db/migrations/002_create_members.rb

@@ -5,7 +5,8 @@ Sequel.migration do
 
       foreign_key :account_id, :accounts,
         type: :Bignum,
-        null: false
+        null: false,
+        on_delete: :cascade
 
       String :kind, null: false
       String :first_name