Add missing call to whirly_stop.
Add missing call to whirly_stop.

- You wouldn't notice running a single command, but running
  `rspec` made it very apparent -- whirly kept running
  between tests.

exosite/MrMurano,tadpol/MuranoCLI,exosite/MrMurano,tadpol/MuranoCLI,tadpol/MuranoCLI