* CI/CircleCI: Push docker images to DockerHub
Push docker image to DockerHub is DOCKERHUB_PUSH_IMAGES environmental variable is set to "TRUE".
* Build in Release only if pushing the images to dockerhub
* Move branch from repository name to tag name
* Update docker readme
Co-authored-by: Trond B. Krokli <[email protected]>
(cherry picked from commit 84ad438d15cffd7dca0e67d540cd41946b946bed)