Update Intervals first try

UpdateIntervals1.swift

func updateIntervals() { 
  if (intervals.count == 0) { 
    return; 
  } 
  
  let currentInterval = intervals.first! 
  if currentIntervalProgress == 0.0 { 
    currentColor = currentInterval.color() 
    speedLabel.text = currentInterval.description() 
    alertSpeed(currentInterval) 
    currentIntervalProgress += updateInterval 
  } else if currentIntervalProgress >= currentInterval.runFor() { 
    currentIntervalProgress = 0.0 intervals.removeAtIndex(0) 
  } else { 
    currentIntervalProgress += updateInterval 
  } 
}