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>

Dockerfile

@@ -42,6 +42,7 @@ RUN set -x \
 
 ENV GOPATH /usr/share/gocode:/go
 ENV PATH $GOPATH/bin:/usr/share/gocode/bin:$PATH
+RUN go version
 RUN go get golang.org/x/lint/golint
 WORKDIR /go/src/github.com/containers/skopeo
 COPY . /go/src/github.com/containers/skopeo

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