Improve automatic emails with temporary urls

This MR targets the improvement for automatic emails concerning validation of new users by supervisors/re-validation of users.

Fixes #542 (closed)

Fixes #550 (closed)

beat/web/ui/registration/models.py

@@ -43,6 +43,7 @@ from django.utils.translation import ugettext_lazy as _
 
 from ...accounts.models import SupervisionTrack
 from ...accounts.models import Profile
+from ...accounts.models import TemporaryUrl
 from ...utils import mail
 
 SHA1_RE = re.compile("^[a-f0-9]{40}$")
@@ -143,10 +144,14 @@ class RegistrationManager(models.Manager):
                         parsed_url.hostname,
                     )
 
+                    temp_url = TemporaryUrl()
+                    temp_url._generate_temporary_url(TemporaryUrl.VALIDATION, supervisiontrack)
+
                     context = {
                         "supervisor": supervisor_user,
                         "supervisee": user,
                         "prefix": server_address,
+                        "temp_url": temp_url.url_hash,
                     }
 
                     mail.send_email(