Run dub build with all generated files in /tmp

[Christian Köstlin]

Sometimes I do not only rely on git to transport dub projects from
computer to computer, but also on Dropbox or Syncthing or similar
tools. For that it would be great if it would be possible to do all
dub commands (e.g. build) in a way, that they are not touching the
current working directory. For `dub run` I found the option
`--temp-build` that builds to /tmp, but I did not find a similar
option for dub build.

Is there some way to have all files generated by dub out of the project 
folder?

Kind regards,
Christian