Artem Kuzmenko

Add possibility to limit maxConcurrentWorkers in workerFarm

2

On virtual machines no limited(limited by os.cpus) workerFarm use many thread and fail with coredump. Maybe we can add some environment variable for redefine default `maxConcurrentWorkers` in: https://github.com/zkat/cipm/blob/89afe145f4c9342100470d712f11623062d8fdac/lib/extract.js#L13-L16 More details...