Docker Push doesn't allow environment variables

It is a follow up for: 

• https://bitbucket.org/atlassian/bamboo-docker-plugin/issues/29/docker-push-doesnt-allow-environment
• https://bitbucket.org/atlassian/bamboo-docker-plugin/issues/30/new-release-of-this-plugin-planned

When trying to push a docker image to a private registry, it asks for the location. The location is actually part of the image name which could be constructed during the docker build task using environment variables (e.g. ${bamboo.my_image_name}:${bamboo.planRepository.revision}). In order for me to do this and be able to push the image, the Push task needs to all me to specify the same variables as the Repository value. Currently it will give me an error stating that "You must specify a registry address when pushing to a custom registry"