修复部分代码风格的问题

admin/views.py

@@ -1,4 +1,5 @@
 # coding=utf-8
+import os
 from django.conf import settings
 from django.http import HttpResponse, Http404
 
@@ -7,7 +8,7 @@ from rest_framework.views import APIView
 
 class AdminTemplateView(APIView):
     def get(self, request, template_dir, template_name):
-        path = settings.TEMPLATES[0]["DIRS"][0] + "/admin/" + template_dir + "/" + template_name + ".html"
+        path = os.path.join(settings.TEMPLATES[0]["DIRS"][0], "admin", template_dir, template_name + ".html")
         try:
             return HttpResponse(open(path).read(), content_type="text/html")
         except IOError: