Added a setting where the exported excel files should be stored.

Added a option to send the exported excel as mail attachment.

src/events/models.py

@@ -4,7 +4,7 @@ import os
 from ckeditor.fields import RichTextField
 from django.conf import settings
 from django.core.exceptions import ValidationError
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 from django.db import models
 from django.db.models import Q
 from django.template.defaultfilters import slugify