fixes for django2

notes/models.py

@@ -104,13 +104,14 @@ class Note(models.Model):
 
     sujet = models.ForeignKey(
                         Sujet,
+                        on_delete=models.CASCADE,
                         related_name="notes",
-                        on_delete=models.CASCADE
                         )
     text = models.TextField("Texte")
 
     created_by = models.ForeignKey(
                         'utilisateurs.Professionnel',
+                        on_delete=models.SET_NULL,
                         blank=True,
                         null=True
                         )

notes/urls.py

@@ -2,6 +2,8 @@ from django.conf.urls import url
 
 from . import views
 
+app_name = "notes"
+
 urlpatterns = [
     url(r'^$', views.IndexView.as_view(), name="index"),
     url(r'sujets/$', views.SujetListView.as_view(), name="liste-sujet"),