Docker image labels may be confusing

[christophbrgr]

The naming scheme for Docker image labels on Docker Hub may be confusing, e.g. modelhub/keras:1.0.2 may be interpreted as an updated version of keras:1.0.1, but can be a completely different (lower or higher) version of keras with another backend.
I suggest a move to a label scheme which does not imply any versioning in the traditional sense. One suggestion would be to use a simple numerical identifier for the labels, e.g. modelhub/keras:103 and modelhub/keras:237 which can be chosen by the submitting authors.