Seeding Error

2019_05_01_185455_create_categories_table.php

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateCategoriesTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('categories', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->string('name', 128)->unique();
            $table->string('slug', 191)->unique();
            $table->tinyInteger('active')->default(1);
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('categories');
    }
}

2019_05_01_185854_create_products_table.php

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateProductsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('products', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->unsignedBigInteger('category_id');
            $table->string('name');
            $table->string('slug')->unique();
            $table->text('description');
            $table->unsignedBigInteger('quantity');
            $table->decimal('price', 15);
            $table->tinyInteger('active')->default(1);
            $table->foreign('category_id')->references('id')->on('categories')->onDelete('cascade');
            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('products');
    }
}

CategoryTableSeeder.php

<?php

use Illuminate\Database\Seeder;
use App\Category;

class CategoryTableSeeder extends Seeder
{
    /**
     * Run the database seeds.
     *
     * @return void
     */
    public function run()
    {
        //
        $categories = ['Laravel Developer','Web Developer','E-Commerce Developer'];


        foreach($categories as $category){
            Category::create([
                'name' => $category,
                'slug' => str_slug($category),
                'description' => str_random(120),
                ]);
        }
    }
}

DatabaseSeeder.php

<?php

use Illuminate\Database\Seeder;

class DatabaseSeeder extends Seeder
{
    /**
     * Seed the application's database.
     *
     * @return void
     */
    public function run()
    {
        // $this->call(UsersTableSeeder::class);
        // $this->call(CategoryTableSeeder::class);
       //  $this->call(ProductTableSeeder::class);

       // factory(App\Category::class,7)->create();
      // factory(App\Product::class,20)->create();

    }
}

Model____Product.php

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Product extends Model
{
    //
     /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $guarded = [''];

    public $timestamps = false;


}

Model___Category.php

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Category extends Model
{
    //
     /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $guarded = [''];

    public $timestamps = false;
}

ProductTableSeeder.php

<?php

use Illuminate\Database\Seeder;
use App\Product;
use Carbon\Carbon;

class ProductTableSeeder extends Seeder
{

    public function run()
    {
       // $products= ['Hotel Management','School Management'];
        for ($i=1; $i <= 100 ; $i++){
            Product::create([
                'category_id' => rand(1,5),
                'name' => 'Product' .$i,
                'slug' => str_slug('Product' .$i),
                'description' => str_random(120),
                'quantity' => rand(1,10),
                'price' => rand(100,5000),
                'created_at' => Carbon::now(),
                'updated_at' => Carbon::now(),
                ]);
        }
    }
}

Here Is Error