大幅优化数据库查询, 升级django至1.11 LTS, 升级python至3.6.2

submission/migrations/0005_submission_username.py

@@ -0,0 +1,21 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.4 on 2017-08-26 03:47
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('submission', '0004_auto_20170717_1324'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='submission',
+            name='username',
+            field=models.CharField(default="", max_length=30),
+            preserve_default=False,
+        ),
+    ]