Croupier version v0.3.1 is out

What's Changed

• Inotify support by @ralsina in #1

  This adds the TaskManager.auto_run method that monitors task inputs and
  reruns tasks as needed, and TaskManager.auto_stop to stop it.

  This will be useful for Hacé (the croupier-based make-like) and Nicolino
  (a SSG)

  Here's an example from the tests:

    x = 0
    counter = TaskProc.new { x += 1; x.to_s }
    Task.new(output: "t1", inputs: ["i"], proc: counter)
    TaskManager.auto_run
    # We need to yield or else the watch callbacks never run
    Fiber.yield
    File.open("i", "w") << "foo"
    Fiber.yield
    TaskManager.auto_stop
    # It should have run
    (x > 0).should be_true

Full Changelog: v0.3.0...v0.3.1