修改和删除 contest 和 problem 部分字段

problem/migrations/0010_auto_20151017_1226.py

@@ -0,0 +1,24 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('problem', '0009_auto_20151008_1125'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='problem',
+            name='last_update_time',
+            field=models.DateTimeField(null=True, blank=True),
+        ),
+        migrations.AlterField(
+            model_name='problem',
+            name='source',
+            field=models.CharField(max_length=200, null=True, blank=True),
+        ),
+    ]

problem/migrations/0011_auto_20151017_1227.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+import utils.models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('problem', '0010_auto_20151017_1226'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='problem',
+            name='hint',
+            field=utils.models.RichTextField(null=True, blank=True),
+        ),
+    ]