dmake.build arguments "--build-args"

[rapatel0]

It would be nice if we have build arguments added to the yaml file that passes through to the --build-args flag in the docker build command.

When I get a chance I'll try to dig more into the code and understand it to see if I can code it up and submit a pull request.

[jizhilong]

@rapatel0 very useful feature, actually it has been waiting in my TODO list for quit a long time, it would be great if you can propose a PR.