golang Dockerfile now using multistage build

[JoelPagliuca]

Slightly changed the Dockerfile for GoLang projects to match the newer multistage build style

[msftclas]

All CLA requirements met.

[floydpink]

@JoelPagliuca - as you might have already seen, the CircleCI build is failing because it is using NodeJS v4 - I'd pushed this commit as part of another PR that I opened a while ago.

You might want to include (rebase/cherry-pick) that into this PR as well... :)

[JoelPagliuca]

sure thing, haven't pulled cherry picked before, do you have a series of commands I can run to cherry-pick 0c046372abee7b431c8b8ec6c24cd62c40022ba7 into my multistage-golang branch?

[floydpink]

These might help: https://stackoverflow.com/questions/5120038/is-it-possible-to-cherry-pick-a-commit-from-another-git-repository/5120074#5120074 https://stackoverflow.com/questions/2474353/how-to-copy-commits-from-one-branch-to-another/2474430#2474430

…

On Sat, Oct 6, 2018 at 3:51 AM Joel Pagliuca ***@***.***> wrote: sure thing, haven't pulled cherry picked before, do you have a series of commands I can run to cherry-pick 0c04637 into my multistage-golang branch? — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#145 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAKcQAHE3aesNTDvQWhuWdD5mh7mbnAdks5uiGEZgaJpZM4XKNEc> .

[JoelPagliuca]

awesome, great finds, thanks for the help