Add redir model, remove children albums

gallery/models/redir.py

@@ -0,0 +1,14 @@
+from django.db import models
+
+from gallery.models import Album
+
+
+class Redir(models.Model):
+    path = models.CharField(max_length=255, db_index=True, unique=True, verbose_name="Path")
+    album = models.ForeignKey(Album, on_delete=models.CASCADE, related_name='pathurl', verbose_name="Album")
+
+    class Meta:
+        verbose_name_plural = "Redirs"
+
+    def __str__(self):
+        return '{0} - {1}'.format(self.path, self.album.slug)