Publish newest images to dockerhub

[kramer65]

Problem
I'm trying to use a pgrouting image in my setup. The images on dockerhub have not been updated for about two years though, so pulling from there gives me outdated images. The images in this repo seem to be updated more frequently.

Improvement
Can these images (preferably automatically) be pushed to dockerhub, so that we can simply base our setup on the latest there.

Alternatives
The alternative we're now looking at is copy-pasting the Dockerfiles from this repo into our own. That is obviously not a sustainable method, and creates more complicated Dockerfiles in our own repo, so we would prefer using the images from dockerhub.

[cayetanobv]

Unfortunately, as you can see in this issue, we can not use Dockerhub anymore to automate builds because Docker changed the use policy. We need to plan new ways to automate builds. Remember we are a little organization mainly composed of volunteers. Thank you for your interest @kramer65 .

[cvvergara]

Policy has changed back, this needs to be reviewed.