MLOPS-83 - Remove Docker config file

[tvinagre]

Removes docker default configuration file.

There are 3 ways to do this:

1. Add a mock JSON file with the credentials, similar to the default one (found in ~/.docker/config.json) (can still be uploaded to GIT or other service by user error so I don't think it's a good solution)
2. Use username and password and encode them using base64
3. Receive the docker-base64-encoded credentials and pass them to kubernetes secret (my choice)

In the end, the secret expects a JSON with the folowing format:

{ "auths": { "https://index.docker.io/v1/": { "auth": "${base64encode("${var.registry_username}:${var.registry_password}")}" } } }

[tvinagre]

@michcio1234 I just checked, MLFLow doesn't have an official Docker Images, so we're building it and sending it to our repo. https://hub.docker.com/r/drtools/mlflow This image is Public now though, so this credentials should not be needed. I'll add to the documentation and add them as optional.