ci/travis: upgdate go version to 1.7.1 and remove 1.6.3 & fix install
ci/travis: upgdate go version to 1.7.1 and remove 1.6.3 & fix install

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

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