I am currently trying to perform several steps that require tasks to be spawned into child processes. For example:

1. Watch files
2. Start up my Static Site Generator's Preview Server

I can easily use a tasks like [grunt-concurrent](https://github.com/sindresorhus/grunt-concurrent) to have both of these run simultaneously. However, when I exit grunt, the child process (in this case - the static site generator which I am running using [grunt-shell](https://github.com/sindresorhus/grunt-shell)) keeps running. I would like to have these tasks run simultaneously - but also have them be killed when grunt exits.

Thoughts?