Add global env & Caching brew dir
Add global env & Caching brew dir

Go related env
Valid brew cache?
brew make jobs 9

Signed-off-by: Koichi Shiraishi <2e5bdfebde234ed3509bcfc18121c70b6631e207@gmail.com>

zchee/docker-machine-driver-xhyve,zchee/docker-machine-driver-xhyve