Closes #9798 @maintainers please note that this is a change to the UX. We no longer require the -f flag on `docker tag` to move a tag from an existing image. However, this does make us more consistent across our commands, see https://github.com/docker/docker/issues/9798 for the history. Signed-off-by: Doug Davis <dug@us.ibm.com> Upstream-commit: 8d4fe141c4c3f456df9c2be75ffe5071d1665717 Component: engine