format code

problem/urls/admin.py

@@ -1,6 +1,6 @@
 from django.conf.urls import url
 
-from ..views.admin import ProblemAPI, TestCaseUploadAPI, ContestProblemAPI
+from ..views.admin import ContestProblemAPI, ProblemAPI, TestCaseUploadAPI
 
 urlpatterns = [
     url(r"^test_case/upload/?$", TestCaseUploadAPI.as_view(), name="test_case_upload_api"),