修改判题设置；增加web 和 mongodb 数据库的操作

submission/serializers.py

@@ -0,0 +1,10 @@
+# coding=utf-8
+from rest_framework import serializers
+
+
+
+class CreateSubmissionSerializer(serializers.Serializer):
+    problem_id = serializers.IntegerField()
+    language = serializers.IntegerField()
+    code = serializers.CharField(max_length=3000)
+