Add golang information to --version flag
@ayufan Can you make gitlab-ci-multi-runner to output information similar to
docker version. This would make it easier to open issues - at least if it's a go issue.
% docker version Client: Version: 1.8.2 API version: 1.20 Go version: go1.5.1 Git commit: 0a8c2e3-dirty Built: Mon Sep 14 12:09:36 UTC 2015 OS/Arch: linux/amd64