Content scheduled at the same time plays all at once

[jmillerv]

Presumably, a schedule would avoid two programs playing at the same time. In the event that there are overlapping programs in a schedule, go-dj plays them all simultaneously. This ticket should create a check to ensure that only 1 program is playing at a time.

As it stands this feels like a boolean variable that is set to true when play begins and set to false when it ends. The loop should check if anything is playing before spawning additional go routines.