feat(client): use unix pipes with config:push

[Joshua-Anderson]

This was briefly discussed as a V2 thing in deis/deis#4675 and deis/deis#4697.

I personally like it cause it's more unixy, but I understand if this is rejected because this is really a personal preference thing 😃.

If there is interest I will make the same change for config:pull.

[helgi]

Can't we support both?

[Joshua-Anderson]

There isn't any technical reason we can't. I figured it would be confusing to offer two ways to do the same thing, but I don't have any strong feelings either way.

[arschles]

IMO we should support both, but doesn't have to be blocking for this PR

[technosophos]

@Joshua-Anderson We're getting close to freezing an Alpha of Deis v2. In your opinion, is this a risky one for us to try to merge at the last minute? Or should we wait until after Alpha.

[Joshua-Anderson]

@technosophos Works on my machine (Ubuntu 15.10) ™️ 😃

I think merging this more of a decision if this change is desirable (some people may prefer flags over pipes). It's a small scoped and pretty easily testable change, so it wouldn't be too much work to land ( I have no idea how soon you want to release or how busy you are 😃)

If this doesn't make it into the alpha, can backwards compatible changes still land in V2 before the GA release?

This change also needs a complimentary change to config:pull to support pipes as well, but I was hanging off on that until this change was approved or rejected. So releasing one without the other would leave an odd UX where pull and push behaved differently.

[arschles]

@Joshua-Anderson I think it's wise to implement config:pull in this patch as well

[Joshua-Anderson]

I think it's wise to implement config:pull in this patch as well

Ok. Sounds good! I'm super busy right now, but if I have some time I'll fix it up.

[Joshua-Anderson]

@arschles I updated this PR to support both pipes and command line arguments.

[arschles]

@Joshua-Anderson cool. My LGTM1 stands, but it looks like you need a rebase now

[Joshua-Anderson]

😦 As a side effect of enabling required status (which I am totally 👍 on), every time there is a commit on master, PRs are required to update before merging (to prevent accidental test breakage), which is a little annoying.

[bacongobbler]

hmm, that might be why everything needs to be rebased all the time. deis/deis does not have that enabled so that might be the bug. Definitely annoying :)