Maximum concurrency queue in Swift

This repo has a quick demo of a class implementing a queue which allows for a certain number of concurrently executing tasks. This is typically used to protect a resource that only allows a certain number of concurrent connections. Otherwise GCD is pretty good at managing active numbers of tasks on its own.

Running this application, you'll see:

• Hello, World! printed to the console.
• One hundred instances of Task: N printed to the console in (by default) batches of five.
• Goodbye, World! as the program terminates.

As you've probably guessed, the maximum concurrency set up in the demo in main.swift is five.