Fix vkey reconstruction for PollMessage (#823)

* Fix vkey reconstruction for PollMessage

* Add foreign key

* Rebase on HEAD

db/src/main/resources/sql/flyway/V60__remove_pollmessage_sequence.sql

@@ -0,0 +1,36 @@
+-- Copyright 2020 The Nomulus Authors. All Rights Reserved.
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+
+alter table "PollMessage" alter column poll_message_id drop default;
+
+drop sequence "PollMessage_poll_message_id_seq";
+
+alter table "PollMessage" rename column "domain_revision_id" to "domain_history_revision_id";
+alter table "PollMessage" rename column "contact_revision_id" to "contact_history_revision_id";
+alter table "PollMessage" rename column "host_revision_id" to "host_history_revision_id";
+
+alter table if exists "PollMessage"
+   add constraint fk_poll_message_domain_history
+   foreign key (domain_repo_id, domain_history_revision_id)
+   references "DomainHistory";
+
+alter table if exists "PollMessage"
+   add constraint fk_poll_message_contact_history
+   foreign key (contact_repo_id, contact_history_revision_id)
+   references "ContactHistory";
+
+alter table if exists "PollMessage"
+   add constraint fk_poll_message_host_history
+   foreign key (host_repo_id, host_history_revision_id)
+   references "HostHistory";