Make it possible to control build status using exit codes
It may be an interesting feature to be able to control build status using
.gitlab-ci.yml and exit codes.
Using the environment variables may be quite simple yet powerful approach.
my-job: script: - echo Hello world! status: success: [0, 21] warning: 
my-job: variables: SKIP_EXIT_STATUS: 137 CANCEL_EXIT_STATUS: 138 script: # ...
It would be used by gitlab-ce!8121
Idea from @ayufan during Slack conversation :)