Create-react-app: CI Failing

[heyimalex]

All of our CI builds on windows have been failing since ~July 2. Check it out. I manually ran the process again on our last _successful_ build, and that failed too, so I'm pretty sure no particular commit caused it, just some change out of our hands.

The errors is always kill: not enough arguments and triggered by this line in stopLocalRegistry. I _think_ this is pretty much the _very last step_ in all of our tasks.

I'm not sure why verdaccio isn't showing up in the output of ps -ef, but if it's not a _huge_ deal if the process isn't killed, maybe we can add the -r flag to the call to xargs? Anyway, figured I'd open up an issue to track.

[heyimalex]

I tried using -r in #7385 and it worked for windows but apparently mac's xargs doesn't support that as an option :')