修改并完善比赛及其他部分的内容及测试

contest/migrations/0002_contest_visible.py

@@ -0,0 +1,19 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('contest', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='contest',
+            name='visible',
+            field=models.BooleanField(default=True),
+        ),
+    ]