修正代码格式；删除不用的依赖

account/models.py

@@ -71,6 +71,5 @@ class UserProfile(models.Model):
     phone_number = models.CharField(max_length=15, blank=True, null=True)
     school = models.CharField(max_length=200, blank=True, null=True)
 
-
     class Meta:
         db_table = "user_profile"

oj/settings.py

@@ -59,7 +59,6 @@ INSTALLED_APPS = (
     'judge',
     'judge_dispatcher',
 
-    'django_extensions',
     'rest_framework',
     'huey.djhuey',
 )
@@ -106,7 +105,7 @@ WSGI_APPLICATION = 'oj.wsgi.application'
 # Internationalization
 # https://docs.djangoproject.com/en/1.8/topics/i18n/
 
-LANGUAGE_CODE = 'zh-cn'
+LANGUAGE_CODE = 'zh-hans'
 
 TIME_ZONE = 'Asia/Shanghai'