Change primary key of DelegationSignerData and add its history table (#841)

* Change primary key of DelegationSignerData and add its history table

* Change primary key and resolve comments

* Rebase on HEAD

db/src/main/resources/sql/flyway/V69__change_primary_key_and_add_history_table_for_delegation_signer.sql

@@ -0,0 +1,35 @@
+-- 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 "DelegationSignerData" drop constraint "DelegationSignerData_pkey";
+
+alter table "DelegationSignerData"
+    add constraint "DelegationSignerData_pkey"
+    primary key (domain_repo_id, key_tag, algorithm, digest_type, digest);
+
+create table "DomainDsDataHistory" (
+    ds_data_history_revision_id int8 not null,
+    algorithm int4 not null,
+    digest bytea not null,
+    digest_type int4 not null,
+    domain_history_revision_id int8 not null,
+    key_tag int4 not null,
+    domain_repo_id text,
+    primary key (ds_data_history_revision_id)
+);
+
+alter table if exists "DomainDsDataHistory"
+    add constraint FKo4ilgyyfnvppbpuivus565i0j
+    foreign key (domain_repo_id, domain_history_revision_id)
+    references "DomainHistory";