Small fixes for Warnings found by PyCharm, mostly spellingerrors.

src/events/mixins.py

@@ -1,4 +1,5 @@
 """Mixins for Events."""
+from django.core.exceptions import ImproperlyConfigured
 from django.db.models import Q
 from django.http import Http404
 from django.shortcuts import get_object_or_404
@@ -32,8 +33,7 @@ class EventDetailMixin(object):
     event = None
 
     def get_context_data(self, **kwargs):
-        """Add self.event or the related event of self.object to the template
-        context.
+        """Add this event or the related event of the given object to the template context.
 
         :return: TemplateContext object"""
         context = super(EventDetailMixin, self).get_context_data(**kwargs)