New flag to oc new-build to produce no output

[rhcarvalho]

Closes #5296.

[rhcarvalho]

@bparees @smarterclayton PTAL
[test]

[openshift-bot]

Evaluated for origin test up to 96fd8c2

[bparees]

add a validation error if they specify "--to" or "--to-docker" and "--no-output"?

[openshift-bot]

continuous-integration/openshift-jenkins/test SUCCESS (https://ci.openshift.redhat.com/jenkins/job/test_pull_requests_origin/7534/)

[rhcarvalho]

add a validation error if they specify "--to" or "--to-docker" and "--no-output"?

I had thought of it and tried that out earlier and chose to not attempt to throw errors and simply produce no output (meaning --no-output takes precedence).

Reasoning (AFAICT):

1. there's no standard way in cobra to declare mutually exclusive flags.

2. there's no clean way to tell whether a flag was not provided vs. it was provided with the zero-value for its type. Unless manually reparsing the args, these would behave the same:

   oc new-build <src> --to-docker=false --to '' --no-output
   oc new-build <src> --no-output
   

[bparees]

good enough for me. thanks.
[merge]

[openshift-bot]

continuous-integration/openshift-jenkins/merge SUCCESS (https://ci.openshift.redhat.com/jenkins/job/merge_pull_requests_origin/4184/) (Image: devenv-rhel7_2835)

[openshift-bot]

Evaluated for origin merge up to 96fd8c2