CC-2098: Only push playlists that havent ended yet

-implemented. Removed ability to specify time ranges for now, and defaulted to looking from now to 24 hours ahead.
Being able to specify time ranges was removed, since we are not using bi-directional communication between pypofetch and Airtime server.

python_apps/pypo/test/airtime-schedule-insert.php

@@ -79,7 +79,7 @@ $endTime = date("Y-m-d H:i:s", time()+(60*60));
 
 echo "Removing everything from the scheduler between $startTime and $endTime...";
 // Scheduler: remove any playlists for the next hour
-Schedule::RemoveItemsInRange($startTime, $endTime);
+//Schedule::RemoveItemsInRange($startTime, $endTime);
 // Check for succcess
 $scheduleClear = Schedule::isScheduleEmptyInRange($startTime, "01:00:00");
 if (!$scheduleClear) {