This test case shows an issue with pubnub where the actual exit of the program takes a few minutes (not seconds, as I'd expect). I'm running it on my laptop (a Macbook Pro).
See run.txt for 10 runs of the test. For example, this snippet:
done! 2017-04-30 19:42:09.836880
Sun Apr 30 19:46:45 PDT 2017
Shows that it took over 4 minutes from the time the last line was executed until the program actually stopped and returned control back to the console.