minor fixes

bda/models.py

@@ -158,7 +158,8 @@ class Participant(models.Model):
                                    blank=True)
     tirage = models.ForeignKey(Tirage)
     choicesrevente = models.ManyToManyField(Spectacle,
-                                            related_name="revente")
+                                            related_name="revente",
+                                            blank=True)
 
     def __str__(self):
         return "%s - %s" % (self.user, self.tirage.title)

bda/views.py

@@ -20,6 +20,7 @@ from django.utils import timezone
 from django.views.generic.list import ListView
 
 import time
+from datetime import timedelta
 
 from gestioncof.decorators import cof_required, buro_required
 from bda.models import Spectacle, Participant, ChoixSpectacle, Attribution,\