homebrew does internal caching in ARGV that prevents us from doing the
`ARGV.clear; ARGV << 'newarg'` trick twice.
rather than try to further reach in to homebrew's innards, i figure it's
better to just pass multiple arguments down to homebrew code at once,
since it already supports that
refs #47
this delegates to homebrew's uninstall to get its work done. vanilla
`brew uninstall` actually works, but this gives us a more consistent
interface.
as discussed in #47
should address #33
includes cleanup and tests
i'm not crazy about leaning on installing/uninstalling caffeine in the
tests. it makes for some unnecessarily heavy tests and downloads. but
i'd rather get tests in place first then fix the warts.
I chose Caffeine since it's relatively small to download. Eventually I'd
like to switch this up so we bundle a dmg, zip, etc that the test suite
wires in to verify that we do the Right Thing (tm) with all those file
types. Probably will want to support `file://` URLs in Casks to help us
for that use case.
phinze