Log the version of the go toolchain

Before we use "go get" in CI, run "go version" so that we can be sure of
which version of the toolchain we're using.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>

hack/travis_osx.sh

@@ -8,6 +8,7 @@ _containers="${GOPATH}/src/github.com/containers"
 mkdir -vp ${_containers}
 ln -vsf $(pwd) ${_containers}/skopeo
 
+go version
 go get -u github.com/cpuguy83/go-md2man golang.org/x/lint/golint
 
 cd ${_containers}/skopeo