Allow 0 minutes before/after schedule, fix room sorting

includes/model/Room_model.php

@@ -36,7 +36,7 @@ function Room_validate_name(string $name, int $room_id)
  */
 function Rooms()
 {
-    return Room::all()->sortBy('name');
+    return Room::orderBy('name')->get();
 }
 
 /**

includes/pages/schedule/ImportSchedule.php

@@ -130,8 +130,8 @@ class ImportSchedule extends BaseController
             'name'           => 'required',
             'url'            => 'required',
             'shift_type'     => 'required|int',
-            'minutes_before' => 'required|int',
+            'minutes_before' => 'int',
-            'minutes_after'  => 'required|int',
+            'minutes_after'  => 'int',
         ]);
 
         if (!isset($this->getShiftTypes()[$data['shift_type']])) {