php artisan migrate でずっこけたとき

$ php artisan migrate
Migration table created successfully.
Migrating: 2014_10_12_000000_create_users_table

   Illuminate\Database\QueryException  : SQLSTATE[42000]: Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes (SQL: alter table `users` add unique `users_email_unique`(`email`))

  at /home/kusanagi/yoyaku/laravel/vendor/laravel/framework/src/Illuminate/Database/Connection.php:665
    661|         // If an exception occurs when attempting to run a query, we'll format the error
    662|         // message to include the bindings with SQL, which will make this exception a
    663|         // lot more helpful to the developer instead of just the database's errors.
    664|         catch (Exception $e) {
  > 665|             throw new QueryException(
    666|                 $query, $this->prepareBindings($bindings), $e
    667|             );
    668|         }
    669|

  Exception trace:

  1   PDOException::("SQLSTATE[42000]: Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes")
      /home/kusanagi/yoyaku/laravel/vendor/laravel/framework/src/Illuminate/Database/Connection.php:459

  2   PDOStatement::execute()
      /home/kusanagi/yoyaku/laravel/vendor/laravel/framework/src/Illuminate/Database/Connection.php:459

  Please use the argument -v to see more details.

namespace App\Providers;

use Illuminate\Support\ServiceProvider;
use Illuminate\Support\Facades\Schema;  <----追記

class AppServiceProvider extends ServiceProvider
{
    /**
     * Register any application services.
     *
     * @return void
     */
    public function register()
    {
        //
    }

    /**
     * Bootstrap any application services.
     *
     * @return void
     */
    public function boot()
    {
        Schema::defaultStringLength(191);  <----追記
    }
}

$ php artisan migrate