Use a SQL date object for LocalDates (#842)

* Use a SQL date object for LocalDates

* Clean up comment

db/src/main/resources/sql/flyway/V65__local_date_date_type.sql

@@ -0,0 +1,15 @@
+-- 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 "Spec11ThreatMatch" ALTER COLUMN "check_date" TYPE date USING check_date::date;