add vagrant style build for go_segment

This PR is to build a base box for go_segment to speed up our Jenkins build times. We were not able to get the packer approach to building boxes working, because of the private SG cookbooks. Instead we used Vagrant, Berkshelf, and `vagrant package` to build the box, see the README in `go_segment_base` directory.

Let me know if there are questions or feeback, or if you prefer I PR this to a topic branch since it's so different.
So we need the latest and greatest from git. In all the "released" versions of this cookbook, including the ones in the chef repos (which I assume is where the one we have came from), the GOPATH is created as the root user. We wanted this to be configurable, so we could create it as Vagrant user for the VM, which it now is on github, but hasn't been released yet.