Fix material cover save path

apps/course/migrations/0010_auto_20180129_1501.py

@@ -0,0 +1,18 @@
+# Generated by Django 2.0.1 on 2018-01-29 15:01
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('course', '0009_auto_20180129_1458'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='material',
+            name='cover',
+            field=models.ImageField(upload_to='materials', verbose_name='Фон материала'),
+        ),
+    ]

apps/course/models.py

@@ -103,7 +103,7 @@ class Lesson(models.Model):
 
 class Material(models.Model):
     title = models.CharField('Название материала', max_length=100)
-    cover = models.ImageField('Фон материала', upload_to='lessons')
+    cover = models.ImageField('Фон материала', upload_to='materials')
     short_description = models.TextField('Краткое описание материала')
 
     created_at = models.DateTimeField(auto_now_add=True)