varchar(255)で収まるわけないので作りなおす

database/migrations/2018_06_08_014226_recreate_metadata_table.php

@@ -0,0 +1,37 @@
+<?php
+
+use Illuminate\Support\Facades\Schema;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Database\Migrations\Migration;
+
+class RecreateMetadataTable extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        Schema::dropIfExists('metadata');
+        Schema::create('metadata', function (Blueprint $table) {
+            $table->text('url');
+            $table->text('title');
+            $table->text('description');
+            $table->text('image');
+            $table->timestamps();
+
+            $table->index('url');
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        Schema::dropIfExists('metadata');
+    }
+}