Debugging

I was reading your readme, and saw you mentioned debugging. Why not offer it properly? A debug option? And from the CLI a --debug flag?

It should be easy enough to debug serial tests? I guess since node-test isn't going to support spawnin of new processes, debugging directly should be possible.

However debugging is broken in Node.js 5.2.
nodejs/node#4297

From CLI this could be done simple. A debug flag that activate the serial option and other things related to debugging. This will make it easy for JetBrains. Intellij or VS Code.

What is your progress with the CLI ?