update to django 2.2

Author: Shoker174

seo/migrations/0001_initial.py

@@ -19,7 +19,7 @@ class Migration(migrations.Migration):
                 ('description', models.CharField(default=b'', max_length=200, verbose_name='Description', blank=True)),
                 ('keywords', models.CharField(default=b'', max_length=1000, verbose_name='Keywords', blank=True)),
                 ('object_id', models.PositiveIntegerField()),
-                ('content_type', models.ForeignKey(to='contenttypes.ContentType')),
+                ('content_type', models.ForeignKey(on_delete=models.deletion.CASCADE, to='contenttypes.ContentType')),
             ],
             options={
                 'verbose_name': 'SEO fields',

seo/models.py

@@ -19,11 +19,11 @@ class Meta:
     keywords = models.CharField(verbose_name=_('Keywords'),
         max_length=1000, default='', blank=True)
 
-    content_type = models.ForeignKey(ContentType)
+    content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
     object_id = models.PositiveIntegerField()
     content_object = GenericForeignKey('content_type', 'object_id')
 
-    def __unicode__(self):
+    def __str__(self):
         return self.title
 
 
@@ -39,5 +39,5 @@ class Meta:
     def get_absolute_url(self):
         return self.url
 
-    def __unicode__(self):
+    def __str__(self):
         return self.url