testresult: Fix the date timestamp to update every time

The intention for that field was to be the time stamp of the last test
result update. Unfortunately, I used the idiom for 'created' time
stamps instead of 'updated' ones.

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>

patchwork/migrations/0011_test_results_updated_ts_fix.py

@@ -0,0 +1,19 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('patchwork', '0010_test_results_to_cc_list'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='testresult',
+            name='date',
+            field=models.DateTimeField(auto_now=True),
+        ),
+    ]

patchwork/models.py

@@ -644,7 +644,7 @@ class TestResult(models.Model):
     revision = models.ForeignKey(SeriesRevision, blank=True, null=True)
     patch = models.ForeignKey(Patch, blank=True, null=True)
     user = models.ForeignKey(User)
-    date = models.DateTimeField(default=datetime.datetime.now)
+    date = models.DateTimeField(auto_now=True)
     state = models.SmallIntegerField(choices=STATE_CHOICES)
     url = models.URLField(blank=True, null=True)
     summary = models.TextField(blank=True, null=True)