[FIX] Remove an old migration
[FIX] Typo
[IMP] Add a new column in the talk model and a new relationship in the event.
[IMP] Add a level in the talk form.
[IMP] Add the title "Time Slot"
[IMP] Move the Flask-Admin configuration to the admin file.
[FIX] Move the Schedule to the right template
[IMP] Add a new link in the main menu to access the administration panel.