Correctly report errors returned by commands
Correctly report errors returned by commands

When running our various subcommands, report errors that they return
correctly, and ensure that in those cases we don't exit with status 0.

Signed-off-by: Nalin Dahyabhai <f562fcb2a0b898bf0be1afc867ea92325d8f825f@redhat.com>

rhatdan/buildah,nalind/buildah,TomSweeneyRedHat/buildah,ipbabble/buildah,projectatomic/buildah,TomSweeneyRedHat/buildah,projectatomic/buildah,rhatdan/buildah,nalind/buildah,rhatdan/buildah,nalind/buildah-1,nalind/buildah-1,nalind/buildah-1,ipbabble/buildah,projectatomic/buildah,TomSweeneyRedHat/buildah