Use pool recyling.

See a lot of (OperationalError) SSL SYSCALL error: EOF detected errors. I think this is caused by SSL timeouts. Hopefully setting the pool recyling to 1h will make these disappear
Split next bus logic into sperate function.

I want to reuse this code in multiple places.
Use the Departures_dereferenced view for next bus logic

The SQL view de-normalises bus stop deltas etc so timetable data can be quickly looked up.
Add a next bus api endpoint

Just need to provide a stop_id to get results.