fix(homebrew): fix bad `homebrew tap` invocation
fix(homebrew): fix bad `homebrew tap` invocation

This was a misport (see b0d5ca3f0fcb20d69277b476d2a94b91cbe9161c) which
you'd only catch on a fresh install; I didn't see it because I obviously
already had the tap.

Closes: https://github.com/wincent/wincent/issues/88

wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent