title: ErrorException array to string conversion on migrate --seed
body: <p>I'm trying to set up my very first laravel project however when I try to have artisan to seed the database with faker it throws </p>
  
  <blockquote>
    <p>[errorException] array to string conversion</p>
  </blockquote>
  
  <p>I'm just working with the stock users migration file
  and using the command php artisan migrate --seed</p>
  
  <p>Any guidance would be greatly appreciated</p>
  
  <pre><code>use Illuminate\Database\Schema\Blueprint;
  use Illuminate\Database\Migrations\Migration;
  
  class CreateUsersTable extends Migration
  {
  /**
   * Run the migrations.
   *
   * @return void
   */
  public function up()
  {
      Schema::create('users', function (Blueprint $table) {
          $table-&gt;increments('id');
          $table-&gt;string('name');
          $table-&gt;string('email')-&gt;unique();
          $table-&gt;string('password', 60);
          $table-&gt;string('role', array('user', 'admin', 'superuser'));
          $table-&gt;rememberToken();
          $table-&gt;timestamps();
      });
  }
  
  /**
   * Reverse the migrations.
   *
   * @return void
   */
  public function down()
  {
      Schema::drop('users');
  }
  }
  </code></pre>
  
  <p>and this UserTableSeeder that artisan generated for me</p>
  
  <pre><code>use Illuminate\Database\Seeder;
  
  class UserTableSeeder extends Seeder
  {
  /**
   * Run the database seeds.
   *
   * @return void
   */
  public function run()
  {
      factory(App\User::class, 49)-&gt;create();
      factory(App\User::class)-&gt;create([
          'name' =&gt; 'admin',
          'role' =&gt; 'admin',
      ]);
  }
  }
  </code></pre>
  
  <p>this is my Modelfactory.php</p>
  
  <pre><code>$factory-&gt;define(App\User::class, function ($faker) {
  return [
      'name' =&gt; $faker-&gt;name,
      'email' =&gt; $faker-&gt;email,
      'password' =&gt; str_random(10),
      'remember_token' =&gt; str_random(10),
      'role' =&gt; $faker-&gt;word-&gt;randomElement(array('user','superuser')),
  ];
  });
  </code></pre>