Update dependencies

See merge request !332

- beat.backend.python to 1.7.7

- beat.backend.python to 1.7.7

Improve automatic emails with temporary urls

Closes #550 and #542

See merge request !328

Fixes #550

[accounts/ui][templates] page/message for supervision revokation (supervisee yearly revalidation notification)

[ui][views/registration-templates] add quick link accept for new supervisor for already valid supervisee

[accounts][views] implement rejection endpoint and notify supervisor of revalidation through quick link

[accounts][management][commands] Generate temporary url through model manager for yearly account revalidation

for newly created users

Fixes #542