Prior to this commit, docker would look for a container ID based on
"Successfully built" string. This output does not exist if a user has
enabled the experimental feature buildkit. This commit updates the build
behavior to match against both kinds of outputs, and instead of using
`scan`, it uses MatchData and groups the container id with match group
name `:id` instead of making hard assumptions with the matches being
contained inside arrays from scan.
4d70856b8a