Make all default send_* funcs return result of `<message_class>.sen…

…d()` (#277)

Right now 2 implicitly return this already, and 2 explicitly only return `True` if it gets that far.

Note that the `modeled.ModelInvitation`'s version already does exactly this explicitly.

src/organizations/backends/defaults.py

@@ -128,7 +128,7 @@ def send_reminder(self, user, sender=None, **kwargs):
             return False
         token = PasswordResetTokenGenerator().make_token(user)
         kwargs.update({"token": token})
-        self.email_message(
+        return self.email_message(
             user, self.reminder_subject, self.reminder_body, sender, **kwargs
         ).send()
 
@@ -230,7 +230,7 @@ def send_activation(self, user, sender=None, **kwargs):
             return False
         token = self.get_token(user)
         kwargs.update({"token": token})
-        self.email_message(
+        return self.email_message(
             user, self.activation_subject, self.activation_body, sender, **kwargs
         ).send()
 
@@ -337,10 +337,9 @@ def send_invitation(self, user, sender=None, **kwargs):
             return False
         token = self.get_token(user)
         kwargs.update({"token": token})
-        self.email_message(
+        return self.email_message(
             user, self.invitation_subject, self.invitation_body, sender, **kwargs
         ).send()
-        return True
 
     def send_notification(self, user, sender=None, **kwargs):
         """
@@ -350,7 +349,6 @@ def send_notification(self, user, sender=None, **kwargs):
         """
         if not user.is_active:
             return False
-        self.email_message(
+        return self.email_message(
             user, self.notification_subject, self.notification_body, sender, **kwargs
         ).send()
-        return True