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The make publish command helps me to put the docker images on docker hub, but that's not enough, we want use Makefile to be able:

1. Tag the new release with a version number, example openwisp/openwisp-base:0.1.0 (Images with latest tag should also be uploaded.)
2. User to easily upload images in their own docker hub account, example atb00ker/openwisp-base:0.1.0
3. Release nightly image directly from the master branch as openwisp/openwisp-base:nightly
4. Upload the nightly images to github releases as well. (Automatically from master branch.)