Security vulnerability in `concurrently` -> `tree-kill`

A security vulnerability has recently been reported for a nested dependency:
```nps-utils> concurrently > tree-kill```
https://npmjs.com/advisories/1432

Concurrently has updated it's dependencies to address the vulnerability:
https://github.com/kimmobrunfeldt/concurrently/releases/tag/v5.0.2

Updating to `concurrently@v5.0.2` ought to remediate the vulnerability.
I attempted to do so in a fork, but tests fail for me so I can't confidently make the updates.

Thank you for this great project along with `nps`, it's really brought clarity to npm scripts in my projects.

Start by locating the dependency declaration for nps-utils and reviewing the failed tests from the attempted concurrently update. Verify that upgrading to concurrently v5.0.2 resolves the nested tree-kill advisory, then run the project test suite and confirm it passes.

Written by the indexing model from the issue text.