Imrpove migrations

db/migrations/001_create_rodauth_tables.rb

@@ -35,7 +35,8 @@ Sequel.migration do
     create_table(:account_password_hashes) do
       foreign_key :id, :accounts,
         primary_key: true,
-        type: :Bignum
+        type: :Bignum,
+        on_delete: :cascade
 
       String :password_hash, null: false
     end
@@ -43,7 +44,8 @@ Sequel.migration do
     create_table(:account_verification_keys) do
       foreign_key :id, :accounts,
         primary_key: true,
-        type: :Bignum
+        type: :Bignum,
+        on_delete: :cascade
 
       String :key, null: false