fix: changed publishedAt to Int/number type

backend/prisma/migrations/20220617021322_init/migration.sql

+/*
+  Warnings:
+
+  - Changed the type of `publishedAt` on the `Movie` table. No cast exists, the column would be dropped and recreated, which cannot be done if there is data, since the column is required.
+
+*/
+-- AlterTable
+ALTER TABLE "Movie" DROP COLUMN "publishedAt",
+ADD COLUMN     "publishedAt" INTEGER NOT NULL;
+
+-- CreateIndex
+CREATE UNIQUE INDEX "Movie_originalName_publishedAt_directorId_key" ON "Movie"("originalName", "publishedAt", "directorId");