Appliances that require Docker during build are (currently) unbuildable

[OnGle]

Currently docker does not work during build-time. As such any appliance which requires docker during build-time cannot build.

Currently the only appliance I know of that this issue effects is processmaker

[JedMeister]

FWIW, I just noticed that whilst the processmaker readme suggests docker is required, I can't actually see it being used anywhere?! Perhaps I'm missing something?