Update Lesson model

apps/course/migrations/0024_auto_20180208_0824.py

@@ -0,0 +1,19 @@
+# Generated by Django 2.0.2 on 2018-02-08 08:24
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('course', '0023_auto_20180208_0714'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='lesson',
+            name='cover',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='lesson_covers', to='content.ImageObject', verbose_name='Обложка урока'),
+        ),
+    ]

apps/course/models.py

@@ -105,8 +105,11 @@ class Lesson(models.Model):
     title = models.CharField('Название урока', max_length=100)
     short_description = models.TextField('Краткое описание урока')
     course = models.ForeignKey(Course, on_delete=models.CASCADE, related_name='lessons')
-    cover = models.ImageField('Фон урока', upload_to='lessons')
+    cover = models.ForeignKey(
-
+        ImageObject, related_name='lesson_covers',
+        verbose_name='Обложка урока', on_delete=models.CASCADE,
+        null=True, blank=True,
+    )
     created_at = models.DateTimeField(auto_now_add=True)
     update_at = models.DateTimeField(auto_now=True)