Laravel 5 项目的更新问题

请教各位大神能否帮忙解决这个问题？
和别人合作一个项目，从git服务器上pull后，使用composer update更新依赖，然后就是各种报错，项目跑不起来。。。终端报错如下：

[RuntimeException]                                                                                         
  Error Output: PHP Notice:  date_default_timezone_set(): Timezone ID '' is invalid in /home/hudengjin/Work  
  Space/project/ideas-library/vendor/laravel/framework/src/Illuminate/Foundation/Bootstrap/LoadConfiguratio  
  n.php on line 41                                                                                           
  PHP Fatal error:  Call to undefined method Illuminate\Foundation\Bootstrap\ConfigureLogging::configureHan  
  dler() in /home/hudengjin/WorkSpace/project/ideas-library/vendor/laravel/framework/src/Illuminate/Foundat  
  ion/Bootstrap/ConfigureLogging.php on line 55 

跪求大神帮忙解决！！！急急急