Expose `count` inside `SwiftQueueManager`

[hang321]

Hi, is it possible to expose the number of jobs in SwiftQueueManager?

public func count() -> Int {
  return manage.values.count
}

[lucas34]

Should be possible but if we do so I suggest we have 2 methods
queueCount() -> Int and jobCount().

[hang321]

I submitted a pull request #160

[lucas34]

Merged