Minimal image based on python:slim and pip install mlflow==1.6.0

Ubuntu based builder image with git and golang installed.

Just to keep DRY installing (via apk) of ca-certs, tini and curl have been extracted to this base.

Adds (presumably stable HEAD version of) glide via 'go get' to the std golang docker image

To be used as primary image on CircleCI builds together with docker and ecr.

Adds curl, nodejs (most notably npm) v7.x and yarnpkg v0.19.0